diff --git a/sys/kern/kern_exit.c b/sys/kern/kern_exit.c index 75177ec96d06..72f09de9cb38 100644 --- a/sys/kern/kern_exit.c +++ b/sys/kern/kern_exit.c @@ -1,1376 +1,1375 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 1982, 1986, 1989, 1991, 1993 * The Regents of the University of California. All rights reserved. * (c) UNIX System Laboratories, Inc. * All or some portions of this file are derived from material licensed * to the University of California by American Telephone and Telegraph * Co. or Unix System Laboratories, Inc. and are reproduced herein with * the permission of UNIX System Laboratories, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)kern_exit.c 8.7 (Berkeley) 2/12/94 */ #include __FBSDID("$FreeBSD$"); #include "opt_ktrace.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* for acct_process() function prototype */ #include #include #include #include #include #ifdef KTRACE #include #endif #include #include #include #include #include #include #include #include #include #ifdef KDTRACE_HOOKS #include dtrace_execexit_func_t dtrace_fasttrap_exit; #endif SDT_PROVIDER_DECLARE(proc); SDT_PROBE_DEFINE1(proc, , , exit, "int"); struct proc * proc_realparent(struct proc *child) { struct proc *p, *parent; sx_assert(&proctree_lock, SX_LOCKED); if ((child->p_treeflag & P_TREE_ORPHANED) == 0) return (child->p_pptr->p_pid == child->p_oppid ? child->p_pptr : initproc); for (p = child; (p->p_treeflag & P_TREE_FIRST_ORPHAN) == 0;) { /* Cannot use LIST_PREV(), since the list head is not known. */ p = __containerof(p->p_orphan.le_prev, struct proc, p_orphan.le_next); KASSERT((p->p_treeflag & P_TREE_ORPHANED) != 0, ("missing P_ORPHAN %p", p)); } parent = __containerof(p->p_orphan.le_prev, struct proc, p_orphans.lh_first); return (parent); } void reaper_abandon_children(struct proc *p, bool exiting) { struct proc *p1, *p2, *ptmp; sx_assert(&proctree_lock, SX_LOCKED); KASSERT(p != initproc, ("reaper_abandon_children for initproc")); if ((p->p_treeflag & P_TREE_REAPER) == 0) return; p1 = p->p_reaper; LIST_FOREACH_SAFE(p2, &p->p_reaplist, p_reapsibling, ptmp) { LIST_REMOVE(p2, p_reapsibling); p2->p_reaper = p1; p2->p_reapsubtree = p->p_reapsubtree; LIST_INSERT_HEAD(&p1->p_reaplist, p2, p_reapsibling); if (exiting && p2->p_pptr == p) { PROC_LOCK(p2); proc_reparent(p2, p1, true); PROC_UNLOCK(p2); } } KASSERT(LIST_EMPTY(&p->p_reaplist), ("p_reaplist not empty")); p->p_treeflag &= ~P_TREE_REAPER; } static void reaper_clear(struct proc *p) { struct proc *p1; bool clear; sx_assert(&proctree_lock, SX_LOCKED); LIST_REMOVE(p, p_reapsibling); if (p->p_reapsubtree == 1) return; clear = true; LIST_FOREACH(p1, &p->p_reaper->p_reaplist, p_reapsibling) { if (p1->p_reapsubtree == p->p_reapsubtree) { clear = false; break; } } if (clear) proc_id_clear(PROC_ID_REAP, p->p_reapsubtree); } void proc_clear_orphan(struct proc *p) { struct proc *p1; sx_assert(&proctree_lock, SA_XLOCKED); if ((p->p_treeflag & P_TREE_ORPHANED) == 0) return; if ((p->p_treeflag & P_TREE_FIRST_ORPHAN) != 0) { p1 = LIST_NEXT(p, p_orphan); if (p1 != NULL) p1->p_treeflag |= P_TREE_FIRST_ORPHAN; p->p_treeflag &= ~P_TREE_FIRST_ORPHAN; } LIST_REMOVE(p, p_orphan); p->p_treeflag &= ~P_TREE_ORPHANED; } /* * exit -- death of process. */ void sys_sys_exit(struct thread *td, struct sys_exit_args *uap) { exit1(td, uap->rval, 0); /* NOTREACHED */ } /* * Exit: deallocate address space and other resources, change proc state to * zombie, and unlink proc from allproc and parent's lists. Save exit status * and rusage for wait(). Check for child processes and orphan them. */ void exit1(struct thread *td, int rval, int signo) { struct proc *p, *nq, *q, *t; struct thread *tdt; ksiginfo_t *ksi, *ksi1; int signal_parent; mtx_assert(&Giant, MA_NOTOWNED); KASSERT(rval == 0 || signo == 0, ("exit1 rv %d sig %d", rval, signo)); p = td->td_proc; /* * XXX in case we're rebooting we just let init die in order to * work around an unsolved stack overflow seen very late during * shutdown on sparc64 when the gmirror worker process exists. * XXX what to do now that sparc64 is gone... remove if? */ if (p == initproc && rebooting == 0) { printf("init died (signal %d, exit %d)\n", signo, rval); panic("Going nowhere without my init!"); } /* * Deref SU mp, since the thread does not return to userspace. */ td_softdep_cleanup(td); /* * MUST abort all other threads before proceeding past here. */ PROC_LOCK(p); /* * First check if some other thread or external request got * here before us. If so, act appropriately: exit or suspend. * We must ensure that stop requests are handled before we set * P_WEXIT. */ thread_suspend_check(0); while (p->p_flag & P_HADTHREADS) { /* * Kill off the other threads. This requires * some co-operation from other parts of the kernel * so it may not be instantaneous. With this state set * any thread entering the kernel from userspace will * thread_exit() in trap(). Any thread attempting to * sleep will return immediately with EINTR or EWOULDBLOCK * which will hopefully force them to back out to userland * freeing resources as they go. Any thread attempting * to return to userland will thread_exit() from userret(). * thread_exit() will unsuspend us when the last of the * other threads exits. * If there is already a thread singler after resumption, * calling thread_single will fail; in that case, we just * re-check all suspension request, the thread should * either be suspended there or exit. */ if (!thread_single(p, SINGLE_EXIT)) /* * All other activity in this process is now * stopped. Threading support has been turned * off. */ break; /* * Recheck for new stop or suspend requests which * might appear while process lock was dropped in * thread_single(). */ thread_suspend_check(0); } KASSERT(p->p_numthreads == 1, ("exit1: proc %p exiting with %d threads", p, p->p_numthreads)); racct_sub(p, RACCT_NTHR, 1); /* Let event handler change exit status */ p->p_xexit = rval; p->p_xsig = signo; /* * Ignore any pending request to stop due to a stop signal. * Once P_WEXIT is set, future requests will be ignored as * well. */ p->p_flag &= ~P_STOPPED_SIG; KASSERT(!P_SHOULDSTOP(p), ("exiting process is stopped")); /* Note that we are exiting. */ p->p_flag |= P_WEXIT; /* * Wait for any processes that have a hold on our vmspace to * release their reference. */ while (p->p_lock > 0) msleep(&p->p_lock, &p->p_mtx, PWAIT, "exithold", 0); PROC_UNLOCK(p); /* Drain the limit callout while we don't have the proc locked */ callout_drain(&p->p_limco); #ifdef AUDIT /* * The Sun BSM exit token contains two components: an exit status as * passed to exit(), and a return value to indicate what sort of exit * it was. The exit status is WEXITSTATUS(rv), but it's not clear * what the return value is. */ AUDIT_ARG_EXIT(rval, 0); AUDIT_SYSCALL_EXIT(0, td); #endif /* Are we a task leader with peers? */ if (p->p_peers != NULL && p == p->p_leader) { mtx_lock(&ppeers_lock); q = p->p_peers; while (q != NULL) { PROC_LOCK(q); kern_psignal(q, SIGKILL); PROC_UNLOCK(q); q = q->p_peers; } while (p->p_peers != NULL) msleep(p, &ppeers_lock, PWAIT, "exit1", 0); mtx_unlock(&ppeers_lock); } /* * Check if any loadable modules need anything done at process exit. * E.g. SYSV IPC stuff. * Event handler could change exit status. * XXX what if one of these generates an error? */ EVENTHANDLER_DIRECT_INVOKE(process_exit, p); /* * If parent is waiting for us to exit or exec, * P_PPWAIT is set; we will wakeup the parent below. */ PROC_LOCK(p); stopprofclock(p); p->p_ptevents = 0; /* * Stop the real interval timer. If the handler is currently * executing, prevent it from rearming itself and let it finish. */ if (timevalisset(&p->p_realtimer.it_value) && _callout_stop_safe(&p->p_itcallout, CS_EXECUTING, NULL) == 0) { timevalclear(&p->p_realtimer.it_interval); msleep(&p->p_itcallout, &p->p_mtx, PWAIT, "ritwait", 0); KASSERT(!timevalisset(&p->p_realtimer.it_value), ("realtime timer is still armed")); } PROC_UNLOCK(p); umtx_thread_exit(td); /* * Reset any sigio structures pointing to us as a result of * F_SETOWN with our pid. */ funsetownlst(&p->p_sigiolst); /* * Close open files and release open-file table. * This may block! */ fdescfree(td); /* * If this thread tickled GEOM, we need to wait for the giggling to * stop before we return to userland */ if (td->td_pflags & TDP_GEOM) g_waitidle(); /* * Remove ourself from our leader's peer list and wake our leader. */ if (p->p_leader->p_peers != NULL) { mtx_lock(&ppeers_lock); if (p->p_leader->p_peers != NULL) { q = p->p_leader; while (q->p_peers != p) q = q->p_peers; q->p_peers = p->p_peers; wakeup(p->p_leader); } mtx_unlock(&ppeers_lock); } vmspace_exit(td); killjobc(); (void)acct_process(td); #ifdef KTRACE ktrprocexit(td); #endif /* * Release reference to text vnode */ if (p->p_textvp != NULL) { vrele(p->p_textvp); p->p_textvp = NULL; } /* * Release our limits structure. */ lim_free(p->p_limit); p->p_limit = NULL; tidhash_remove(td); /* * Call machine-dependent code to release any * machine-dependent resources other than the address space. * The address space is released by "vmspace_exitfree(p)" in * vm_waitproc(). */ cpu_exit(td); WITNESS_WARN(WARN_PANIC, NULL, "process (pid %d) exiting", p->p_pid); /* * Remove from allproc. It still sits in the hash. */ sx_xlock(&allproc_lock); LIST_REMOVE(p, p_list); sx_xunlock(&allproc_lock); sx_xlock(&proctree_lock); PROC_LOCK(p); p->p_flag &= ~(P_TRACED | P_PPWAIT | P_PPTRACE); PROC_UNLOCK(p); /* * Reparent all children processes: * - traced ones to the original parent (or init if we are that parent) * - the rest to init */ q = LIST_FIRST(&p->p_children); if (q != NULL) /* only need this if any child is S_ZOMB */ wakeup(q->p_reaper); for (; q != NULL; q = nq) { nq = LIST_NEXT(q, p_sibling); ksi = ksiginfo_alloc(TRUE); PROC_LOCK(q); q->p_sigparent = SIGCHLD; if ((q->p_flag & P_TRACED) == 0) { proc_reparent(q, q->p_reaper, true); if (q->p_state == PRS_ZOMBIE) { /* * Inform reaper about the reparented * zombie, since wait(2) has something * new to report. Guarantee queueing * of the SIGCHLD signal, similar to * the _exit() behaviour, by providing * our ksiginfo. Ksi is freed by the * signal delivery. */ if (q->p_ksi == NULL) { ksi1 = NULL; } else { ksiginfo_copy(q->p_ksi, ksi); ksi->ksi_flags |= KSI_INS; ksi1 = ksi; ksi = NULL; } PROC_LOCK(q->p_reaper); pksignal(q->p_reaper, SIGCHLD, ksi1); PROC_UNLOCK(q->p_reaper); } else if (q->p_pdeathsig > 0) { /* * The child asked to received a signal * when we exit. */ kern_psignal(q, q->p_pdeathsig); } } else { /* * Traced processes are killed since their existence * means someone is screwing up. */ t = proc_realparent(q); if (t == p) { proc_reparent(q, q->p_reaper, true); } else { PROC_LOCK(t); proc_reparent(q, t, true); PROC_UNLOCK(t); } /* * Since q was found on our children list, the * proc_reparent() call moved q to the orphan * list due to present P_TRACED flag. Clear * orphan link for q now while q is locked. */ proc_clear_orphan(q); q->p_flag &= ~(P_TRACED | P_STOPPED_TRACE); q->p_flag2 &= ~P2_PTRACE_FSTP; q->p_ptevents = 0; FOREACH_THREAD_IN_PROC(q, tdt) { tdt->td_dbgflags &= ~(TDB_SUSPEND | TDB_XSIG | TDB_FSTP); } kern_psignal(q, SIGKILL); } PROC_UNLOCK(q); if (ksi != NULL) ksiginfo_free(ksi); } /* * Also get rid of our orphans. */ while ((q = LIST_FIRST(&p->p_orphans)) != NULL) { PROC_LOCK(q); KASSERT(q->p_oppid == p->p_pid, ("orphan %p of %p has unexpected oppid %d", q, p, q->p_oppid)); q->p_oppid = q->p_reaper->p_pid; /* * If we are the real parent of this process * but it has been reparented to a debugger, then * check if it asked for a signal when we exit. */ if (q->p_pdeathsig > 0) kern_psignal(q, q->p_pdeathsig); CTR2(KTR_PTRACE, "exit: pid %d, clearing orphan %d", p->p_pid, q->p_pid); proc_clear_orphan(q); PROC_UNLOCK(q); } #ifdef KDTRACE_HOOKS if (SDT_PROBES_ENABLED()) { int reason = CLD_EXITED; if (WCOREDUMP(signo)) reason = CLD_DUMPED; else if (WIFSIGNALED(signo)) reason = CLD_KILLED; SDT_PROBE1(proc, , , exit, reason); } #endif /* Save exit status. */ PROC_LOCK(p); p->p_xthread = td; #ifdef KDTRACE_HOOKS /* * Tell the DTrace fasttrap provider about the exit if it * has declared an interest. */ if (dtrace_fasttrap_exit) dtrace_fasttrap_exit(p); #endif /* * Notify interested parties of our demise. */ KNOTE_LOCKED(p->p_klist, NOTE_EXIT); /* * If this is a process with a descriptor, we may not need to deliver * a signal to the parent. proctree_lock is held over * procdesc_exit() to serialize concurrent calls to close() and * exit(). */ signal_parent = 0; if (p->p_procdesc == NULL || procdesc_exit(p)) { /* * Notify parent that we're gone. If parent has the * PS_NOCLDWAIT flag set, or if the handler is set to SIG_IGN, * notify process 1 instead (and hope it will handle this * situation). */ PROC_LOCK(p->p_pptr); mtx_lock(&p->p_pptr->p_sigacts->ps_mtx); if (p->p_pptr->p_sigacts->ps_flag & (PS_NOCLDWAIT | PS_CLDSIGIGN)) { struct proc *pp; mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx); pp = p->p_pptr; PROC_UNLOCK(pp); proc_reparent(p, p->p_reaper, true); p->p_sigparent = SIGCHLD; PROC_LOCK(p->p_pptr); /* * Notify parent, so in case he was wait(2)ing or * executing waitpid(2) with our pid, he will * continue. */ wakeup(pp); } else mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx); if (p->p_pptr == p->p_reaper || p->p_pptr == initproc) { signal_parent = 1; } else if (p->p_sigparent != 0) { if (p->p_sigparent == SIGCHLD) { signal_parent = 1; } else { /* LINUX thread */ signal_parent = 2; } } } else PROC_LOCK(p->p_pptr); sx_xunlock(&proctree_lock); if (signal_parent == 1) { childproc_exited(p); } else if (signal_parent == 2) { kern_psignal(p->p_pptr, p->p_sigparent); } /* Tell the prison that we are gone. */ prison_proc_free(p->p_ucred->cr_prison); /* * The state PRS_ZOMBIE prevents other proesses from sending * signal to the process, to avoid memory leak, we free memory * for signal queue at the time when the state is set. */ sigqueue_flush(&p->p_sigqueue); sigqueue_flush(&td->td_sigqueue); /* * We have to wait until after acquiring all locks before * changing p_state. We need to avoid all possible context * switches (including ones from blocking on a mutex) while * marked as a zombie. We also have to set the zombie state * before we release the parent process' proc lock to avoid * a lost wakeup. So, we first call wakeup, then we grab the * sched lock, update the state, and release the parent process' * proc lock. */ wakeup(p->p_pptr); cv_broadcast(&p->p_pwait); sched_exit(p->p_pptr, td); PROC_SLOCK(p); p->p_state = PRS_ZOMBIE; PROC_UNLOCK(p->p_pptr); /* * Save our children's rusage information in our exit rusage. */ PROC_STATLOCK(p); ruadd(&p->p_ru, &p->p_rux, &p->p_stats->p_cru, &p->p_crux); PROC_STATUNLOCK(p); /* * Make sure the scheduler takes this thread out of its tables etc. * This will also release this thread's reference to the ucred. * Other thread parts to release include pcb bits and such. */ thread_exit(); } #ifndef _SYS_SYSPROTO_H_ struct abort2_args { char *why; int nargs; void **args; }; #endif int sys_abort2(struct thread *td, struct abort2_args *uap) { struct proc *p = td->td_proc; struct sbuf *sb; void *uargs[16]; int error, i, sig; /* * Do it right now so we can log either proper call of abort2(), or * note, that invalid argument was passed. 512 is big enough to * handle 16 arguments' descriptions with additional comments. */ sb = sbuf_new(NULL, NULL, 512, SBUF_FIXEDLEN); sbuf_clear(sb); sbuf_printf(sb, "%s(pid %d uid %d) aborted: ", p->p_comm, p->p_pid, td->td_ucred->cr_uid); /* * Since we can't return from abort2(), send SIGKILL in cases, where * abort2() was called improperly */ sig = SIGKILL; /* Prevent from DoSes from user-space. */ if (uap->nargs < 0 || uap->nargs > 16) goto out; if (uap->nargs > 0) { if (uap->args == NULL) goto out; error = copyin(uap->args, uargs, uap->nargs * sizeof(void *)); if (error != 0) goto out; } /* * Limit size of 'reason' string to 128. Will fit even when * maximal number of arguments was chosen to be logged. */ if (uap->why != NULL) { error = sbuf_copyin(sb, uap->why, 128); if (error < 0) goto out; } else { sbuf_printf(sb, "(null)"); } if (uap->nargs > 0) { sbuf_printf(sb, "("); for (i = 0;i < uap->nargs; i++) sbuf_printf(sb, "%s%p", i == 0 ? "" : ", ", uargs[i]); sbuf_printf(sb, ")"); } /* * Final stage: arguments were proper, string has been * successfully copied from userspace, and copying pointers * from user-space succeed. */ sig = SIGABRT; out: if (sig == SIGKILL) { sbuf_trim(sb); sbuf_printf(sb, " (Reason text inaccessible)"); } sbuf_cat(sb, "\n"); sbuf_finish(sb); log(LOG_INFO, "%s", sbuf_data(sb)); sbuf_delete(sb); exit1(td, 0, sig); return (0); } #ifdef COMPAT_43 /* * The dirty work is handled by kern_wait(). */ int owait(struct thread *td, struct owait_args *uap __unused) { int error, status; error = kern_wait(td, WAIT_ANY, &status, 0, NULL); if (error == 0) td->td_retval[1] = status; return (error); } #endif /* COMPAT_43 */ /* * The dirty work is handled by kern_wait(). */ int sys_wait4(struct thread *td, struct wait4_args *uap) { struct rusage ru, *rup; int error, status; if (uap->rusage != NULL) rup = &ru; else rup = NULL; error = kern_wait(td, uap->pid, &status, uap->options, rup); if (uap->status != NULL && error == 0 && td->td_retval[0] != 0) error = copyout(&status, uap->status, sizeof(status)); if (uap->rusage != NULL && error == 0 && td->td_retval[0] != 0) error = copyout(&ru, uap->rusage, sizeof(struct rusage)); return (error); } int sys_wait6(struct thread *td, struct wait6_args *uap) { struct __wrusage wru, *wrup; siginfo_t si, *sip; idtype_t idtype; id_t id; int error, status; idtype = uap->idtype; id = uap->id; if (uap->wrusage != NULL) wrup = &wru; else wrup = NULL; if (uap->info != NULL) { sip = &si; bzero(sip, sizeof(*sip)); } else sip = NULL; /* * We expect all callers of wait6() to know about WEXITED and * WTRAPPED. */ error = kern_wait6(td, idtype, id, &status, uap->options, wrup, sip); if (uap->status != NULL && error == 0 && td->td_retval[0] != 0) error = copyout(&status, uap->status, sizeof(status)); if (uap->wrusage != NULL && error == 0 && td->td_retval[0] != 0) error = copyout(&wru, uap->wrusage, sizeof(wru)); if (uap->info != NULL && error == 0) error = copyout(&si, uap->info, sizeof(si)); return (error); } /* * Reap the remains of a zombie process and optionally return status and * rusage. Asserts and will release both the proctree_lock and the process * lock as part of its work. */ void proc_reap(struct thread *td, struct proc *p, int *status, int options) { struct proc *q, *t; sx_assert(&proctree_lock, SA_XLOCKED); PROC_LOCK_ASSERT(p, MA_OWNED); KASSERT(p->p_state == PRS_ZOMBIE, ("proc_reap: !PRS_ZOMBIE")); mtx_spin_wait_unlocked(&p->p_slock); q = td->td_proc; if (status) *status = KW_EXITCODE(p->p_xexit, p->p_xsig); if (options & WNOWAIT) { /* * Only poll, returning the status. Caller does not wish to * release the proc struct just yet. */ PROC_UNLOCK(p); sx_xunlock(&proctree_lock); return; } PROC_LOCK(q); sigqueue_take(p->p_ksi); PROC_UNLOCK(q); /* * If we got the child via a ptrace 'attach', we need to give it back * to the old parent. */ if (p->p_oppid != p->p_pptr->p_pid) { PROC_UNLOCK(p); t = proc_realparent(p); PROC_LOCK(t); PROC_LOCK(p); CTR2(KTR_PTRACE, "wait: traced child %d moved back to parent %d", p->p_pid, t->p_pid); proc_reparent(p, t, false); PROC_UNLOCK(p); pksignal(t, SIGCHLD, p->p_ksi); wakeup(t); cv_broadcast(&p->p_pwait); PROC_UNLOCK(t); sx_xunlock(&proctree_lock); return; } PROC_UNLOCK(p); /* * Remove other references to this process to ensure we have an * exclusive reference. */ sx_xlock(PIDHASHLOCK(p->p_pid)); LIST_REMOVE(p, p_hash); sx_xunlock(PIDHASHLOCK(p->p_pid)); LIST_REMOVE(p, p_sibling); reaper_abandon_children(p, true); reaper_clear(p); PROC_LOCK(p); proc_clear_orphan(p); PROC_UNLOCK(p); leavepgrp(p); if (p->p_procdesc != NULL) procdesc_reap(p); sx_xunlock(&proctree_lock); proc_id_clear(PROC_ID_PID, p->p_pid); PROC_LOCK(p); knlist_detach(p->p_klist); p->p_klist = NULL; PROC_UNLOCK(p); /* * Removal from allproc list and process group list paired with * PROC_LOCK which was executed during that time should guarantee * nothing can reach this process anymore. As such further locking * is unnecessary. */ p->p_xexit = p->p_xsig = 0; /* XXX: why? */ PROC_LOCK(q); ruadd(&q->p_stats->p_cru, &q->p_crux, &p->p_ru, &p->p_rux); PROC_UNLOCK(q); /* * Decrement the count of procs running with this uid. */ (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0); /* * Destroy resource accounting information associated with the process. */ #ifdef RACCT if (racct_enable) { PROC_LOCK(p); racct_sub(p, RACCT_NPROC, 1); PROC_UNLOCK(p); } #endif racct_proc_exit(p); /* * Free credentials, arguments, and sigacts. */ - crfree(p->p_ucred); - proc_set_cred(p, NULL); + proc_unset_cred(p); pargs_drop(p->p_args); p->p_args = NULL; sigacts_free(p->p_sigacts); p->p_sigacts = NULL; /* * Do any thread-system specific cleanups. */ thread_wait(p); /* * Give vm and machine-dependent layer a chance to free anything that * cpu_exit couldn't release while still running in process context. */ vm_waitproc(p); #ifdef MAC mac_proc_destroy(p); #endif KASSERT(FIRST_THREAD_IN_PROC(p), ("proc_reap: no residual thread!")); uma_zfree(proc_zone, p); atomic_add_int(&nprocs, -1); } static int proc_to_reap(struct thread *td, struct proc *p, idtype_t idtype, id_t id, int *status, int options, struct __wrusage *wrusage, siginfo_t *siginfo, int check_only) { struct rusage *rup; sx_assert(&proctree_lock, SA_XLOCKED); PROC_LOCK(p); switch (idtype) { case P_ALL: if (p->p_procdesc == NULL || (p->p_pptr == td->td_proc && (p->p_flag & P_TRACED) != 0)) { break; } PROC_UNLOCK(p); return (0); case P_PID: if (p->p_pid != (pid_t)id) { PROC_UNLOCK(p); return (0); } break; case P_PGID: if (p->p_pgid != (pid_t)id) { PROC_UNLOCK(p); return (0); } break; case P_SID: if (p->p_session->s_sid != (pid_t)id) { PROC_UNLOCK(p); return (0); } break; case P_UID: if (p->p_ucred->cr_uid != (uid_t)id) { PROC_UNLOCK(p); return (0); } break; case P_GID: if (p->p_ucred->cr_gid != (gid_t)id) { PROC_UNLOCK(p); return (0); } break; case P_JAILID: if (p->p_ucred->cr_prison->pr_id != (int)id) { PROC_UNLOCK(p); return (0); } break; /* * It seems that the thread structures get zeroed out * at process exit. This makes it impossible to * support P_SETID, P_CID or P_CPUID. */ default: PROC_UNLOCK(p); return (0); } if (p_canwait(td, p)) { PROC_UNLOCK(p); return (0); } if (((options & WEXITED) == 0) && (p->p_state == PRS_ZOMBIE)) { PROC_UNLOCK(p); return (0); } /* * This special case handles a kthread spawned by linux_clone * (see linux_misc.c). The linux_wait4 and linux_waitpid * functions need to be able to distinguish between waiting * on a process and waiting on a thread. It is a thread if * p_sigparent is not SIGCHLD, and the WLINUXCLONE option * signifies we want to wait for threads and not processes. */ if ((p->p_sigparent != SIGCHLD) ^ ((options & WLINUXCLONE) != 0)) { PROC_UNLOCK(p); return (0); } if (siginfo != NULL) { bzero(siginfo, sizeof(*siginfo)); siginfo->si_errno = 0; /* * SUSv4 requires that the si_signo value is always * SIGCHLD. Obey it despite the rfork(2) interface * allows to request other signal for child exit * notification. */ siginfo->si_signo = SIGCHLD; /* * This is still a rough estimate. We will fix the * cases TRAPPED, STOPPED, and CONTINUED later. */ if (WCOREDUMP(p->p_xsig)) { siginfo->si_code = CLD_DUMPED; siginfo->si_status = WTERMSIG(p->p_xsig); } else if (WIFSIGNALED(p->p_xsig)) { siginfo->si_code = CLD_KILLED; siginfo->si_status = WTERMSIG(p->p_xsig); } else { siginfo->si_code = CLD_EXITED; siginfo->si_status = p->p_xexit; } siginfo->si_pid = p->p_pid; siginfo->si_uid = p->p_ucred->cr_uid; /* * The si_addr field would be useful additional * detail, but apparently the PC value may be lost * when we reach this point. bzero() above sets * siginfo->si_addr to NULL. */ } /* * There should be no reason to limit resources usage info to * exited processes only. A snapshot about any resources used * by a stopped process may be exactly what is needed. */ if (wrusage != NULL) { rup = &wrusage->wru_self; *rup = p->p_ru; PROC_STATLOCK(p); calcru(p, &rup->ru_utime, &rup->ru_stime); PROC_STATUNLOCK(p); rup = &wrusage->wru_children; *rup = p->p_stats->p_cru; calccru(p, &rup->ru_utime, &rup->ru_stime); } if (p->p_state == PRS_ZOMBIE && !check_only) { proc_reap(td, p, status, options); return (-1); } return (1); } int kern_wait(struct thread *td, pid_t pid, int *status, int options, struct rusage *rusage) { struct __wrusage wru, *wrup; idtype_t idtype; id_t id; int ret; /* * Translate the special pid values into the (idtype, pid) * pair for kern_wait6. The WAIT_MYPGRP case is handled by * kern_wait6() on its own. */ if (pid == WAIT_ANY) { idtype = P_ALL; id = 0; } else if (pid < 0) { idtype = P_PGID; id = (id_t)-pid; } else { idtype = P_PID; id = (id_t)pid; } if (rusage != NULL) wrup = &wru; else wrup = NULL; /* * For backward compatibility we implicitly add flags WEXITED * and WTRAPPED here. */ options |= WEXITED | WTRAPPED; ret = kern_wait6(td, idtype, id, status, options, wrup, NULL); if (rusage != NULL) *rusage = wru.wru_self; return (ret); } static void report_alive_proc(struct thread *td, struct proc *p, siginfo_t *siginfo, int *status, int options, int si_code) { bool cont; PROC_LOCK_ASSERT(p, MA_OWNED); sx_assert(&proctree_lock, SA_XLOCKED); MPASS(si_code == CLD_TRAPPED || si_code == CLD_STOPPED || si_code == CLD_CONTINUED); cont = si_code == CLD_CONTINUED; if ((options & WNOWAIT) == 0) { if (cont) p->p_flag &= ~P_CONTINUED; else p->p_flag |= P_WAITED; PROC_LOCK(td->td_proc); sigqueue_take(p->p_ksi); PROC_UNLOCK(td->td_proc); } sx_xunlock(&proctree_lock); if (siginfo != NULL) { siginfo->si_code = si_code; siginfo->si_status = cont ? SIGCONT : p->p_xsig; } if (status != NULL) *status = cont ? SIGCONT : W_STOPCODE(p->p_xsig); PROC_UNLOCK(p); td->td_retval[0] = p->p_pid; } int kern_wait6(struct thread *td, idtype_t idtype, id_t id, int *status, int options, struct __wrusage *wrusage, siginfo_t *siginfo) { struct proc *p, *q; pid_t pid; int error, nfound, ret; bool report; AUDIT_ARG_VALUE((int)idtype); /* XXX - This is likely wrong! */ AUDIT_ARG_PID((pid_t)id); /* XXX - This may be wrong! */ AUDIT_ARG_VALUE(options); q = td->td_proc; if ((pid_t)id == WAIT_MYPGRP && (idtype == P_PID || idtype == P_PGID)) { PROC_LOCK(q); id = (id_t)q->p_pgid; PROC_UNLOCK(q); idtype = P_PGID; } /* If we don't know the option, just return. */ if ((options & ~(WUNTRACED | WNOHANG | WCONTINUED | WNOWAIT | WEXITED | WTRAPPED | WLINUXCLONE)) != 0) return (EINVAL); if ((options & (WEXITED | WUNTRACED | WCONTINUED | WTRAPPED)) == 0) { /* * We will be unable to find any matching processes, * because there are no known events to look for. * Prefer to return error instead of blocking * indefinitely. */ return (EINVAL); } loop: if (q->p_flag & P_STATCHILD) { PROC_LOCK(q); q->p_flag &= ~P_STATCHILD; PROC_UNLOCK(q); } sx_xlock(&proctree_lock); loop_locked: nfound = 0; LIST_FOREACH(p, &q->p_children, p_sibling) { pid = p->p_pid; ret = proc_to_reap(td, p, idtype, id, status, options, wrusage, siginfo, 0); if (ret == 0) continue; else if (ret != 1) { td->td_retval[0] = pid; return (0); } nfound++; PROC_LOCK_ASSERT(p, MA_OWNED); if ((options & WTRAPPED) != 0 && (p->p_flag & P_TRACED) != 0) { PROC_SLOCK(p); report = ((p->p_flag & (P_STOPPED_TRACE | P_STOPPED_SIG)) && p->p_suspcount == p->p_numthreads && (p->p_flag & P_WAITED) == 0); PROC_SUNLOCK(p); if (report) { CTR4(KTR_PTRACE, "wait: returning trapped pid %d status %#x " "(xstat %d) xthread %d", p->p_pid, W_STOPCODE(p->p_xsig), p->p_xsig, p->p_xthread != NULL ? p->p_xthread->td_tid : -1); report_alive_proc(td, p, siginfo, status, options, CLD_TRAPPED); return (0); } } if ((options & WUNTRACED) != 0 && (p->p_flag & P_STOPPED_SIG) != 0) { PROC_SLOCK(p); report = (p->p_suspcount == p->p_numthreads && ((p->p_flag & P_WAITED) == 0)); PROC_SUNLOCK(p); if (report) { report_alive_proc(td, p, siginfo, status, options, CLD_STOPPED); return (0); } } if ((options & WCONTINUED) != 0 && (p->p_flag & P_CONTINUED) != 0) { report_alive_proc(td, p, siginfo, status, options, CLD_CONTINUED); return (0); } PROC_UNLOCK(p); } /* * Look in the orphans list too, to allow the parent to * collect it's child exit status even if child is being * debugged. * * Debugger detaches from the parent upon successful * switch-over from parent to child. At this point due to * re-parenting the parent loses the child to debugger and a * wait4(2) call would report that it has no children to wait * for. By maintaining a list of orphans we allow the parent * to successfully wait until the child becomes a zombie. */ if (nfound == 0) { LIST_FOREACH(p, &q->p_orphans, p_orphan) { ret = proc_to_reap(td, p, idtype, id, NULL, options, NULL, NULL, 1); if (ret != 0) { KASSERT(ret != -1, ("reaped an orphan (pid %d)", (int)td->td_retval[0])); PROC_UNLOCK(p); nfound++; break; } } } if (nfound == 0) { sx_xunlock(&proctree_lock); return (ECHILD); } if (options & WNOHANG) { sx_xunlock(&proctree_lock); td->td_retval[0] = 0; return (0); } PROC_LOCK(q); if (q->p_flag & P_STATCHILD) { q->p_flag &= ~P_STATCHILD; PROC_UNLOCK(q); goto loop_locked; } sx_xunlock(&proctree_lock); error = msleep(q, &q->p_mtx, PWAIT | PCATCH | PDROP, "wait", 0); if (error) return (error); goto loop; } void proc_add_orphan(struct proc *child, struct proc *parent) { sx_assert(&proctree_lock, SX_XLOCKED); KASSERT((child->p_flag & P_TRACED) != 0, ("proc_add_orphan: not traced")); if (LIST_EMPTY(&parent->p_orphans)) { child->p_treeflag |= P_TREE_FIRST_ORPHAN; LIST_INSERT_HEAD(&parent->p_orphans, child, p_orphan); } else { LIST_INSERT_AFTER(LIST_FIRST(&parent->p_orphans), child, p_orphan); } child->p_treeflag |= P_TREE_ORPHANED; } /* * Make process 'parent' the new parent of process 'child'. * Must be called with an exclusive hold of proctree lock. */ void proc_reparent(struct proc *child, struct proc *parent, bool set_oppid) { sx_assert(&proctree_lock, SX_XLOCKED); PROC_LOCK_ASSERT(child, MA_OWNED); if (child->p_pptr == parent) return; PROC_LOCK(child->p_pptr); sigqueue_take(child->p_ksi); PROC_UNLOCK(child->p_pptr); LIST_REMOVE(child, p_sibling); LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); proc_clear_orphan(child); if ((child->p_flag & P_TRACED) != 0) { proc_add_orphan(child, child->p_pptr); } child->p_pptr = parent; if (set_oppid) child->p_oppid = parent->p_pid; } diff --git a/sys/kern/kern_prot.c b/sys/kern/kern_prot.c index a3e7b162e100..4b9aad2ca6dc 100644 --- a/sys/kern/kern_prot.c +++ b/sys/kern/kern_prot.c @@ -1,2282 +1,2288 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 1982, 1986, 1989, 1990, 1991, 1993 * The Regents of the University of California. * (c) UNIX System Laboratories, Inc. * Copyright (c) 2000-2001 Robert N. M. Watson. * All rights reserved. * * All or some portions of this file are derived from material licensed * to the University of California by American Telephone and Telegraph * Co. or Unix System Laboratories, Inc. and are reproduced herein with * the permission of UNIX System Laboratories, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)kern_prot.c 8.6 (Berkeley) 1/21/94 */ /* * System calls related to processes and protection */ #include __FBSDID("$FreeBSD$"); #include "opt_inet.h" #include "opt_inet6.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef REGRESSION FEATURE(regression, "Kernel support for interfaces necessary for regression testing (SECURITY RISK!)"); #endif #include #include static MALLOC_DEFINE(M_CRED, "cred", "credentials"); SYSCTL_NODE(_security, OID_AUTO, bsd, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, "BSD security policy"); static void crsetgroups_locked(struct ucred *cr, int ngrp, gid_t *groups); #ifndef _SYS_SYSPROTO_H_ struct getpid_args { int dummy; }; #endif /* ARGSUSED */ int sys_getpid(struct thread *td, struct getpid_args *uap) { struct proc *p = td->td_proc; td->td_retval[0] = p->p_pid; #if defined(COMPAT_43) if (SV_PROC_FLAG(p, SV_AOUT)) td->td_retval[1] = kern_getppid(td); #endif return (0); } #ifndef _SYS_SYSPROTO_H_ struct getppid_args { int dummy; }; #endif /* ARGSUSED */ int sys_getppid(struct thread *td, struct getppid_args *uap) { td->td_retval[0] = kern_getppid(td); return (0); } int kern_getppid(struct thread *td) { struct proc *p = td->td_proc; return (p->p_oppid); } /* * Get process group ID; note that POSIX getpgrp takes no parameter. */ #ifndef _SYS_SYSPROTO_H_ struct getpgrp_args { int dummy; }; #endif int sys_getpgrp(struct thread *td, struct getpgrp_args *uap) { struct proc *p = td->td_proc; PROC_LOCK(p); td->td_retval[0] = p->p_pgrp->pg_id; PROC_UNLOCK(p); return (0); } /* Get an arbitrary pid's process group id */ #ifndef _SYS_SYSPROTO_H_ struct getpgid_args { pid_t pid; }; #endif int sys_getpgid(struct thread *td, struct getpgid_args *uap) { struct proc *p; int error; if (uap->pid == 0) { p = td->td_proc; PROC_LOCK(p); } else { p = pfind(uap->pid); if (p == NULL) return (ESRCH); error = p_cansee(td, p); if (error) { PROC_UNLOCK(p); return (error); } } td->td_retval[0] = p->p_pgrp->pg_id; PROC_UNLOCK(p); return (0); } /* * Get an arbitrary pid's session id. */ #ifndef _SYS_SYSPROTO_H_ struct getsid_args { pid_t pid; }; #endif int sys_getsid(struct thread *td, struct getsid_args *uap) { return (kern_getsid(td, uap->pid)); } int kern_getsid(struct thread *td, pid_t pid) { struct proc *p; int error; if (pid == 0) { p = td->td_proc; PROC_LOCK(p); } else { p = pfind(pid); if (p == NULL) return (ESRCH); error = p_cansee(td, p); if (error) { PROC_UNLOCK(p); return (error); } } td->td_retval[0] = p->p_session->s_sid; PROC_UNLOCK(p); return (0); } #ifndef _SYS_SYSPROTO_H_ struct getuid_args { int dummy; }; #endif /* ARGSUSED */ int sys_getuid(struct thread *td, struct getuid_args *uap) { td->td_retval[0] = td->td_ucred->cr_ruid; #if defined(COMPAT_43) td->td_retval[1] = td->td_ucred->cr_uid; #endif return (0); } #ifndef _SYS_SYSPROTO_H_ struct geteuid_args { int dummy; }; #endif /* ARGSUSED */ int sys_geteuid(struct thread *td, struct geteuid_args *uap) { td->td_retval[0] = td->td_ucred->cr_uid; return (0); } #ifndef _SYS_SYSPROTO_H_ struct getgid_args { int dummy; }; #endif /* ARGSUSED */ int sys_getgid(struct thread *td, struct getgid_args *uap) { td->td_retval[0] = td->td_ucred->cr_rgid; #if defined(COMPAT_43) td->td_retval[1] = td->td_ucred->cr_groups[0]; #endif return (0); } /* * Get effective group ID. The "egid" is groups[0], and could be obtained * via getgroups. This syscall exists because it is somewhat painful to do * correctly in a library function. */ #ifndef _SYS_SYSPROTO_H_ struct getegid_args { int dummy; }; #endif /* ARGSUSED */ int sys_getegid(struct thread *td, struct getegid_args *uap) { td->td_retval[0] = td->td_ucred->cr_groups[0]; return (0); } #ifndef _SYS_SYSPROTO_H_ struct getgroups_args { u_int gidsetsize; gid_t *gidset; }; #endif int sys_getgroups(struct thread *td, struct getgroups_args *uap) { struct ucred *cred; u_int ngrp; int error; cred = td->td_ucred; ngrp = cred->cr_ngroups; if (uap->gidsetsize == 0) { error = 0; goto out; } if (uap->gidsetsize < ngrp) return (EINVAL); error = copyout(cred->cr_groups, uap->gidset, ngrp * sizeof(gid_t)); out: td->td_retval[0] = ngrp; return (error); } #ifndef _SYS_SYSPROTO_H_ struct setsid_args { int dummy; }; #endif /* ARGSUSED */ int sys_setsid(struct thread *td, struct setsid_args *uap) { struct pgrp *pgrp; int error; struct proc *p = td->td_proc; struct pgrp *newpgrp; struct session *newsess; error = 0; pgrp = NULL; newpgrp = malloc(sizeof(struct pgrp), M_PGRP, M_WAITOK | M_ZERO); newsess = malloc(sizeof(struct session), M_SESSION, M_WAITOK | M_ZERO); sx_xlock(&proctree_lock); if (p->p_pgid == p->p_pid || (pgrp = pgfind(p->p_pid)) != NULL) { if (pgrp != NULL) PGRP_UNLOCK(pgrp); error = EPERM; } else { (void)enterpgrp(p, p->p_pid, newpgrp, newsess); td->td_retval[0] = p->p_pid; newpgrp = NULL; newsess = NULL; } sx_xunlock(&proctree_lock); if (newpgrp != NULL) free(newpgrp, M_PGRP); if (newsess != NULL) free(newsess, M_SESSION); return (error); } /* * set process group (setpgid/old setpgrp) * * caller does setpgid(targpid, targpgid) * * pid must be caller or child of caller (ESRCH) * if a child * pid must be in same session (EPERM) * pid can't have done an exec (EACCES) * if pgid != pid * there must exist some pid in same session having pgid (EPERM) * pid must not be session leader (EPERM) */ #ifndef _SYS_SYSPROTO_H_ struct setpgid_args { int pid; /* target process id */ int pgid; /* target pgrp id */ }; #endif /* ARGSUSED */ int sys_setpgid(struct thread *td, struct setpgid_args *uap) { struct proc *curp = td->td_proc; struct proc *targp; /* target process */ struct pgrp *pgrp; /* target pgrp */ int error; struct pgrp *newpgrp; if (uap->pgid < 0) return (EINVAL); error = 0; newpgrp = malloc(sizeof(struct pgrp), M_PGRP, M_WAITOK | M_ZERO); sx_xlock(&proctree_lock); if (uap->pid != 0 && uap->pid != curp->p_pid) { if ((targp = pfind(uap->pid)) == NULL) { error = ESRCH; goto done; } if (!inferior(targp)) { PROC_UNLOCK(targp); error = ESRCH; goto done; } if ((error = p_cansee(td, targp))) { PROC_UNLOCK(targp); goto done; } if (targp->p_pgrp == NULL || targp->p_session != curp->p_session) { PROC_UNLOCK(targp); error = EPERM; goto done; } if (targp->p_flag & P_EXEC) { PROC_UNLOCK(targp); error = EACCES; goto done; } PROC_UNLOCK(targp); } else targp = curp; if (SESS_LEADER(targp)) { error = EPERM; goto done; } if (uap->pgid == 0) uap->pgid = targp->p_pid; if ((pgrp = pgfind(uap->pgid)) == NULL) { if (uap->pgid == targp->p_pid) { error = enterpgrp(targp, uap->pgid, newpgrp, NULL); if (error == 0) newpgrp = NULL; } else error = EPERM; } else { if (pgrp == targp->p_pgrp) { PGRP_UNLOCK(pgrp); goto done; } if (pgrp->pg_id != targp->p_pid && pgrp->pg_session != curp->p_session) { PGRP_UNLOCK(pgrp); error = EPERM; goto done; } PGRP_UNLOCK(pgrp); error = enterthispgrp(targp, pgrp); } done: sx_xunlock(&proctree_lock); KASSERT((error == 0) || (newpgrp != NULL), ("setpgid failed and newpgrp is NULL")); if (newpgrp != NULL) free(newpgrp, M_PGRP); return (error); } /* * Use the clause in B.4.2.2 that allows setuid/setgid to be 4.2/4.3BSD * compatible. It says that setting the uid/gid to euid/egid is a special * case of "appropriate privilege". Once the rules are expanded out, this * basically means that setuid(nnn) sets all three id's, in all permitted * cases unless _POSIX_SAVED_IDS is enabled. In that case, setuid(getuid()) * does not set the saved id - this is dangerous for traditional BSD * programs. For this reason, we *really* do not want to set * _POSIX_SAVED_IDS and do not want to clear POSIX_APPENDIX_B_4_2_2. */ #define POSIX_APPENDIX_B_4_2_2 #ifndef _SYS_SYSPROTO_H_ struct setuid_args { uid_t uid; }; #endif /* ARGSUSED */ int sys_setuid(struct thread *td, struct setuid_args *uap) { struct proc *p = td->td_proc; struct ucred *newcred, *oldcred; uid_t uid; struct uidinfo *uip; int error; uid = uap->uid; AUDIT_ARG_UID(uid); newcred = crget(); uip = uifind(uid); PROC_LOCK(p); /* * Copy credentials so other references do not see our changes. */ oldcred = crcopysafe(p, newcred); #ifdef MAC error = mac_cred_check_setuid(oldcred, uid); if (error) goto fail; #endif /* * See if we have "permission" by POSIX 1003.1 rules. * * Note that setuid(geteuid()) is a special case of * "appropriate privileges" in appendix B.4.2.2. We need * to use this clause to be compatible with traditional BSD * semantics. Basically, it means that "setuid(xx)" sets all * three id's (assuming you have privs). * * Notes on the logic. We do things in three steps. * 1: We determine if the euid is going to change, and do EPERM * right away. We unconditionally change the euid later if this * test is satisfied, simplifying that part of the logic. * 2: We determine if the real and/or saved uids are going to * change. Determined by compile options. * 3: Change euid last. (after tests in #2 for "appropriate privs") */ if (uid != oldcred->cr_ruid && /* allow setuid(getuid()) */ #ifdef _POSIX_SAVED_IDS uid != oldcred->cr_svuid && /* allow setuid(saved gid) */ #endif #ifdef POSIX_APPENDIX_B_4_2_2 /* Use BSD-compat clause from B.4.2.2 */ uid != oldcred->cr_uid && /* allow setuid(geteuid()) */ #endif (error = priv_check_cred(oldcred, PRIV_CRED_SETUID)) != 0) goto fail; #ifdef _POSIX_SAVED_IDS /* * Do we have "appropriate privileges" (are we root or uid == euid) * If so, we are changing the real uid and/or saved uid. */ if ( #ifdef POSIX_APPENDIX_B_4_2_2 /* Use the clause from B.4.2.2 */ uid == oldcred->cr_uid || #endif /* We are using privs. */ priv_check_cred(oldcred, PRIV_CRED_SETUID) == 0) #endif { /* * Set the real uid and transfer proc count to new user. */ if (uid != oldcred->cr_ruid) { change_ruid(newcred, uip); setsugid(p); } /* * Set saved uid * * XXX always set saved uid even if not _POSIX_SAVED_IDS, as * the security of seteuid() depends on it. B.4.2.2 says it * is important that we should do this. */ if (uid != oldcred->cr_svuid) { change_svuid(newcred, uid); setsugid(p); } } /* * In all permitted cases, we are changing the euid. */ if (uid != oldcred->cr_uid) { change_euid(newcred, uip); setsugid(p); } proc_set_cred(p, newcred); #ifdef RACCT racct_proc_ucred_changed(p, oldcred, newcred); crhold(newcred); #endif PROC_UNLOCK(p); #ifdef RCTL rctl_proc_ucred_changed(p, newcred); crfree(newcred); #endif uifree(uip); crfree(oldcred); return (0); fail: PROC_UNLOCK(p); uifree(uip); crfree(newcred); return (error); } #ifndef _SYS_SYSPROTO_H_ struct seteuid_args { uid_t euid; }; #endif /* ARGSUSED */ int sys_seteuid(struct thread *td, struct seteuid_args *uap) { struct proc *p = td->td_proc; struct ucred *newcred, *oldcred; uid_t euid; struct uidinfo *euip; int error; euid = uap->euid; AUDIT_ARG_EUID(euid); newcred = crget(); euip = uifind(euid); PROC_LOCK(p); /* * Copy credentials so other references do not see our changes. */ oldcred = crcopysafe(p, newcred); #ifdef MAC error = mac_cred_check_seteuid(oldcred, euid); if (error) goto fail; #endif if (euid != oldcred->cr_ruid && /* allow seteuid(getuid()) */ euid != oldcred->cr_svuid && /* allow seteuid(saved uid) */ (error = priv_check_cred(oldcred, PRIV_CRED_SETEUID)) != 0) goto fail; /* * Everything's okay, do it. */ if (oldcred->cr_uid != euid) { change_euid(newcred, euip); setsugid(p); } proc_set_cred(p, newcred); PROC_UNLOCK(p); uifree(euip); crfree(oldcred); return (0); fail: PROC_UNLOCK(p); uifree(euip); crfree(newcred); return (error); } #ifndef _SYS_SYSPROTO_H_ struct setgid_args { gid_t gid; }; #endif /* ARGSUSED */ int sys_setgid(struct thread *td, struct setgid_args *uap) { struct proc *p = td->td_proc; struct ucred *newcred, *oldcred; gid_t gid; int error; gid = uap->gid; AUDIT_ARG_GID(gid); newcred = crget(); PROC_LOCK(p); oldcred = crcopysafe(p, newcred); #ifdef MAC error = mac_cred_check_setgid(oldcred, gid); if (error) goto fail; #endif /* * See if we have "permission" by POSIX 1003.1 rules. * * Note that setgid(getegid()) is a special case of * "appropriate privileges" in appendix B.4.2.2. We need * to use this clause to be compatible with traditional BSD * semantics. Basically, it means that "setgid(xx)" sets all * three id's (assuming you have privs). * * For notes on the logic here, see setuid() above. */ if (gid != oldcred->cr_rgid && /* allow setgid(getgid()) */ #ifdef _POSIX_SAVED_IDS gid != oldcred->cr_svgid && /* allow setgid(saved gid) */ #endif #ifdef POSIX_APPENDIX_B_4_2_2 /* Use BSD-compat clause from B.4.2.2 */ gid != oldcred->cr_groups[0] && /* allow setgid(getegid()) */ #endif (error = priv_check_cred(oldcred, PRIV_CRED_SETGID)) != 0) goto fail; #ifdef _POSIX_SAVED_IDS /* * Do we have "appropriate privileges" (are we root or gid == egid) * If so, we are changing the real uid and saved gid. */ if ( #ifdef POSIX_APPENDIX_B_4_2_2 /* use the clause from B.4.2.2 */ gid == oldcred->cr_groups[0] || #endif /* We are using privs. */ priv_check_cred(oldcred, PRIV_CRED_SETGID) == 0) #endif { /* * Set real gid */ if (oldcred->cr_rgid != gid) { change_rgid(newcred, gid); setsugid(p); } /* * Set saved gid * * XXX always set saved gid even if not _POSIX_SAVED_IDS, as * the security of setegid() depends on it. B.4.2.2 says it * is important that we should do this. */ if (oldcred->cr_svgid != gid) { change_svgid(newcred, gid); setsugid(p); } } /* * In all cases permitted cases, we are changing the egid. * Copy credentials so other references do not see our changes. */ if (oldcred->cr_groups[0] != gid) { change_egid(newcred, gid); setsugid(p); } proc_set_cred(p, newcred); PROC_UNLOCK(p); crfree(oldcred); return (0); fail: PROC_UNLOCK(p); crfree(newcred); return (error); } #ifndef _SYS_SYSPROTO_H_ struct setegid_args { gid_t egid; }; #endif /* ARGSUSED */ int sys_setegid(struct thread *td, struct setegid_args *uap) { struct proc *p = td->td_proc; struct ucred *newcred, *oldcred; gid_t egid; int error; egid = uap->egid; AUDIT_ARG_EGID(egid); newcred = crget(); PROC_LOCK(p); oldcred = crcopysafe(p, newcred); #ifdef MAC error = mac_cred_check_setegid(oldcred, egid); if (error) goto fail; #endif if (egid != oldcred->cr_rgid && /* allow setegid(getgid()) */ egid != oldcred->cr_svgid && /* allow setegid(saved gid) */ (error = priv_check_cred(oldcred, PRIV_CRED_SETEGID)) != 0) goto fail; if (oldcred->cr_groups[0] != egid) { change_egid(newcred, egid); setsugid(p); } proc_set_cred(p, newcred); PROC_UNLOCK(p); crfree(oldcred); return (0); fail: PROC_UNLOCK(p); crfree(newcred); return (error); } #ifndef _SYS_SYSPROTO_H_ struct setgroups_args { u_int gidsetsize; gid_t *gidset; }; #endif /* ARGSUSED */ int sys_setgroups(struct thread *td, struct setgroups_args *uap) { gid_t smallgroups[XU_NGROUPS]; gid_t *groups; u_int gidsetsize; int error; gidsetsize = uap->gidsetsize; if (gidsetsize > ngroups_max + 1) return (EINVAL); if (gidsetsize > XU_NGROUPS) groups = malloc(gidsetsize * sizeof(gid_t), M_TEMP, M_WAITOK); else groups = smallgroups; error = copyin(uap->gidset, groups, gidsetsize * sizeof(gid_t)); if (error == 0) error = kern_setgroups(td, gidsetsize, groups); if (gidsetsize > XU_NGROUPS) free(groups, M_TEMP); return (error); } int kern_setgroups(struct thread *td, u_int ngrp, gid_t *groups) { struct proc *p = td->td_proc; struct ucred *newcred, *oldcred; int error; MPASS(ngrp <= ngroups_max + 1); AUDIT_ARG_GROUPSET(groups, ngrp); newcred = crget(); crextend(newcred, ngrp); PROC_LOCK(p); oldcred = crcopysafe(p, newcred); #ifdef MAC error = mac_cred_check_setgroups(oldcred, ngrp, groups); if (error) goto fail; #endif error = priv_check_cred(oldcred, PRIV_CRED_SETGROUPS); if (error) goto fail; if (ngrp == 0) { /* * setgroups(0, NULL) is a legitimate way of clearing the * groups vector on non-BSD systems (which generally do not * have the egid in the groups[0]). We risk security holes * when running non-BSD software if we do not do the same. */ newcred->cr_ngroups = 1; } else { crsetgroups_locked(newcred, ngrp, groups); } setsugid(p); proc_set_cred(p, newcred); PROC_UNLOCK(p); crfree(oldcred); return (0); fail: PROC_UNLOCK(p); crfree(newcred); return (error); } #ifndef _SYS_SYSPROTO_H_ struct setreuid_args { uid_t ruid; uid_t euid; }; #endif /* ARGSUSED */ int sys_setreuid(struct thread *td, struct setreuid_args *uap) { struct proc *p = td->td_proc; struct ucred *newcred, *oldcred; uid_t euid, ruid; struct uidinfo *euip, *ruip; int error; euid = uap->euid; ruid = uap->ruid; AUDIT_ARG_EUID(euid); AUDIT_ARG_RUID(ruid); newcred = crget(); euip = uifind(euid); ruip = uifind(ruid); PROC_LOCK(p); oldcred = crcopysafe(p, newcred); #ifdef MAC error = mac_cred_check_setreuid(oldcred, ruid, euid); if (error) goto fail; #endif if (((ruid != (uid_t)-1 && ruid != oldcred->cr_ruid && ruid != oldcred->cr_svuid) || (euid != (uid_t)-1 && euid != oldcred->cr_uid && euid != oldcred->cr_ruid && euid != oldcred->cr_svuid)) && (error = priv_check_cred(oldcred, PRIV_CRED_SETREUID)) != 0) goto fail; if (euid != (uid_t)-1 && oldcred->cr_uid != euid) { change_euid(newcred, euip); setsugid(p); } if (ruid != (uid_t)-1 && oldcred->cr_ruid != ruid) { change_ruid(newcred, ruip); setsugid(p); } if ((ruid != (uid_t)-1 || newcred->cr_uid != newcred->cr_ruid) && newcred->cr_svuid != newcred->cr_uid) { change_svuid(newcred, newcred->cr_uid); setsugid(p); } proc_set_cred(p, newcred); #ifdef RACCT racct_proc_ucred_changed(p, oldcred, newcred); crhold(newcred); #endif PROC_UNLOCK(p); #ifdef RCTL rctl_proc_ucred_changed(p, newcred); crfree(newcred); #endif uifree(ruip); uifree(euip); crfree(oldcred); return (0); fail: PROC_UNLOCK(p); uifree(ruip); uifree(euip); crfree(newcred); return (error); } #ifndef _SYS_SYSPROTO_H_ struct setregid_args { gid_t rgid; gid_t egid; }; #endif /* ARGSUSED */ int sys_setregid(struct thread *td, struct setregid_args *uap) { struct proc *p = td->td_proc; struct ucred *newcred, *oldcred; gid_t egid, rgid; int error; egid = uap->egid; rgid = uap->rgid; AUDIT_ARG_EGID(egid); AUDIT_ARG_RGID(rgid); newcred = crget(); PROC_LOCK(p); oldcred = crcopysafe(p, newcred); #ifdef MAC error = mac_cred_check_setregid(oldcred, rgid, egid); if (error) goto fail; #endif if (((rgid != (gid_t)-1 && rgid != oldcred->cr_rgid && rgid != oldcred->cr_svgid) || (egid != (gid_t)-1 && egid != oldcred->cr_groups[0] && egid != oldcred->cr_rgid && egid != oldcred->cr_svgid)) && (error = priv_check_cred(oldcred, PRIV_CRED_SETREGID)) != 0) goto fail; if (egid != (gid_t)-1 && oldcred->cr_groups[0] != egid) { change_egid(newcred, egid); setsugid(p); } if (rgid != (gid_t)-1 && oldcred->cr_rgid != rgid) { change_rgid(newcred, rgid); setsugid(p); } if ((rgid != (gid_t)-1 || newcred->cr_groups[0] != newcred->cr_rgid) && newcred->cr_svgid != newcred->cr_groups[0]) { change_svgid(newcred, newcred->cr_groups[0]); setsugid(p); } proc_set_cred(p, newcred); PROC_UNLOCK(p); crfree(oldcred); return (0); fail: PROC_UNLOCK(p); crfree(newcred); return (error); } /* * setresuid(ruid, euid, suid) is like setreuid except control over the saved * uid is explicit. */ #ifndef _SYS_SYSPROTO_H_ struct setresuid_args { uid_t ruid; uid_t euid; uid_t suid; }; #endif /* ARGSUSED */ int sys_setresuid(struct thread *td, struct setresuid_args *uap) { struct proc *p = td->td_proc; struct ucred *newcred, *oldcred; uid_t euid, ruid, suid; struct uidinfo *euip, *ruip; int error; euid = uap->euid; ruid = uap->ruid; suid = uap->suid; AUDIT_ARG_EUID(euid); AUDIT_ARG_RUID(ruid); AUDIT_ARG_SUID(suid); newcred = crget(); euip = uifind(euid); ruip = uifind(ruid); PROC_LOCK(p); oldcred = crcopysafe(p, newcred); #ifdef MAC error = mac_cred_check_setresuid(oldcred, ruid, euid, suid); if (error) goto fail; #endif if (((ruid != (uid_t)-1 && ruid != oldcred->cr_ruid && ruid != oldcred->cr_svuid && ruid != oldcred->cr_uid) || (euid != (uid_t)-1 && euid != oldcred->cr_ruid && euid != oldcred->cr_svuid && euid != oldcred->cr_uid) || (suid != (uid_t)-1 && suid != oldcred->cr_ruid && suid != oldcred->cr_svuid && suid != oldcred->cr_uid)) && (error = priv_check_cred(oldcred, PRIV_CRED_SETRESUID)) != 0) goto fail; if (euid != (uid_t)-1 && oldcred->cr_uid != euid) { change_euid(newcred, euip); setsugid(p); } if (ruid != (uid_t)-1 && oldcred->cr_ruid != ruid) { change_ruid(newcred, ruip); setsugid(p); } if (suid != (uid_t)-1 && oldcred->cr_svuid != suid) { change_svuid(newcred, suid); setsugid(p); } proc_set_cred(p, newcred); #ifdef RACCT racct_proc_ucred_changed(p, oldcred, newcred); crhold(newcred); #endif PROC_UNLOCK(p); #ifdef RCTL rctl_proc_ucred_changed(p, newcred); crfree(newcred); #endif uifree(ruip); uifree(euip); crfree(oldcred); return (0); fail: PROC_UNLOCK(p); uifree(ruip); uifree(euip); crfree(newcred); return (error); } /* * setresgid(rgid, egid, sgid) is like setregid except control over the saved * gid is explicit. */ #ifndef _SYS_SYSPROTO_H_ struct setresgid_args { gid_t rgid; gid_t egid; gid_t sgid; }; #endif /* ARGSUSED */ int sys_setresgid(struct thread *td, struct setresgid_args *uap) { struct proc *p = td->td_proc; struct ucred *newcred, *oldcred; gid_t egid, rgid, sgid; int error; egid = uap->egid; rgid = uap->rgid; sgid = uap->sgid; AUDIT_ARG_EGID(egid); AUDIT_ARG_RGID(rgid); AUDIT_ARG_SGID(sgid); newcred = crget(); PROC_LOCK(p); oldcred = crcopysafe(p, newcred); #ifdef MAC error = mac_cred_check_setresgid(oldcred, rgid, egid, sgid); if (error) goto fail; #endif if (((rgid != (gid_t)-1 && rgid != oldcred->cr_rgid && rgid != oldcred->cr_svgid && rgid != oldcred->cr_groups[0]) || (egid != (gid_t)-1 && egid != oldcred->cr_rgid && egid != oldcred->cr_svgid && egid != oldcred->cr_groups[0]) || (sgid != (gid_t)-1 && sgid != oldcred->cr_rgid && sgid != oldcred->cr_svgid && sgid != oldcred->cr_groups[0])) && (error = priv_check_cred(oldcred, PRIV_CRED_SETRESGID)) != 0) goto fail; if (egid != (gid_t)-1 && oldcred->cr_groups[0] != egid) { change_egid(newcred, egid); setsugid(p); } if (rgid != (gid_t)-1 && oldcred->cr_rgid != rgid) { change_rgid(newcred, rgid); setsugid(p); } if (sgid != (gid_t)-1 && oldcred->cr_svgid != sgid) { change_svgid(newcred, sgid); setsugid(p); } proc_set_cred(p, newcred); PROC_UNLOCK(p); crfree(oldcred); return (0); fail: PROC_UNLOCK(p); crfree(newcred); return (error); } #ifndef _SYS_SYSPROTO_H_ struct getresuid_args { uid_t *ruid; uid_t *euid; uid_t *suid; }; #endif /* ARGSUSED */ int sys_getresuid(struct thread *td, struct getresuid_args *uap) { struct ucred *cred; int error1 = 0, error2 = 0, error3 = 0; cred = td->td_ucred; if (uap->ruid) error1 = copyout(&cred->cr_ruid, uap->ruid, sizeof(cred->cr_ruid)); if (uap->euid) error2 = copyout(&cred->cr_uid, uap->euid, sizeof(cred->cr_uid)); if (uap->suid) error3 = copyout(&cred->cr_svuid, uap->suid, sizeof(cred->cr_svuid)); return (error1 ? error1 : error2 ? error2 : error3); } #ifndef _SYS_SYSPROTO_H_ struct getresgid_args { gid_t *rgid; gid_t *egid; gid_t *sgid; }; #endif /* ARGSUSED */ int sys_getresgid(struct thread *td, struct getresgid_args *uap) { struct ucred *cred; int error1 = 0, error2 = 0, error3 = 0; cred = td->td_ucred; if (uap->rgid) error1 = copyout(&cred->cr_rgid, uap->rgid, sizeof(cred->cr_rgid)); if (uap->egid) error2 = copyout(&cred->cr_groups[0], uap->egid, sizeof(cred->cr_groups[0])); if (uap->sgid) error3 = copyout(&cred->cr_svgid, uap->sgid, sizeof(cred->cr_svgid)); return (error1 ? error1 : error2 ? error2 : error3); } #ifndef _SYS_SYSPROTO_H_ struct issetugid_args { int dummy; }; #endif /* ARGSUSED */ int sys_issetugid(struct thread *td, struct issetugid_args *uap) { struct proc *p = td->td_proc; /* * Note: OpenBSD sets a P_SUGIDEXEC flag set at execve() time, * we use P_SUGID because we consider changing the owners as * "tainting" as well. * This is significant for procs that start as root and "become" * a user without an exec - programs cannot know *everything* * that libc *might* have put in their data segment. */ td->td_retval[0] = (p->p_flag & P_SUGID) ? 1 : 0; return (0); } int sys___setugid(struct thread *td, struct __setugid_args *uap) { #ifdef REGRESSION struct proc *p; p = td->td_proc; switch (uap->flag) { case 0: PROC_LOCK(p); p->p_flag &= ~P_SUGID; PROC_UNLOCK(p); return (0); case 1: PROC_LOCK(p); p->p_flag |= P_SUGID; PROC_UNLOCK(p); return (0); default: return (EINVAL); } #else /* !REGRESSION */ return (ENOSYS); #endif /* REGRESSION */ } /* * Check if gid is a member of the group set. */ int groupmember(gid_t gid, struct ucred *cred) { int l; int h; int m; if (cred->cr_groups[0] == gid) return(1); /* * If gid was not our primary group, perform a binary search * of the supplemental groups. This is possible because we * sort the groups in crsetgroups(). */ l = 1; h = cred->cr_ngroups; while (l < h) { m = l + ((h - l) / 2); if (cred->cr_groups[m] < gid) l = m + 1; else h = m; } if ((l < cred->cr_ngroups) && (cred->cr_groups[l] == gid)) return (1); return (0); } /* * Test the active securelevel against a given level. securelevel_gt() * implements (securelevel > level). securelevel_ge() implements * (securelevel >= level). Note that the logic is inverted -- these * functions return EPERM on "success" and 0 on "failure". * * Due to care taken when setting the securelevel, we know that no jail will * be less secure that its parent (or the physical system), so it is sufficient * to test the current jail only. * * XXXRW: Possibly since this has to do with privilege, it should move to * kern_priv.c. */ int securelevel_gt(struct ucred *cr, int level) { return (cr->cr_prison->pr_securelevel > level ? EPERM : 0); } int securelevel_ge(struct ucred *cr, int level) { return (cr->cr_prison->pr_securelevel >= level ? EPERM : 0); } /* * 'see_other_uids' determines whether or not visibility of processes * and sockets with credentials holding different real uids is possible * using a variety of system MIBs. * XXX: data declarations should be together near the beginning of the file. */ static int see_other_uids = 1; SYSCTL_INT(_security_bsd, OID_AUTO, see_other_uids, CTLFLAG_RW, &see_other_uids, 0, "Unprivileged processes may see subjects/objects with different real uid"); /*- * Determine if u1 "can see" the subject specified by u2, according to the * 'see_other_uids' policy. * Returns: 0 for permitted, ESRCH otherwise * Locks: none * References: *u1 and *u2 must not change during the call * u1 may equal u2, in which case only one reference is required */ int cr_canseeotheruids(struct ucred *u1, struct ucred *u2) { if (!see_other_uids && u1->cr_ruid != u2->cr_ruid) { if (priv_check_cred(u1, PRIV_SEEOTHERUIDS) != 0) return (ESRCH); } return (0); } /* * 'see_other_gids' determines whether or not visibility of processes * and sockets with credentials holding different real gids is possible * using a variety of system MIBs. * XXX: data declarations should be together near the beginning of the file. */ static int see_other_gids = 1; SYSCTL_INT(_security_bsd, OID_AUTO, see_other_gids, CTLFLAG_RW, &see_other_gids, 0, "Unprivileged processes may see subjects/objects with different real gid"); /* * Determine if u1 can "see" the subject specified by u2, according to the * 'see_other_gids' policy. * Returns: 0 for permitted, ESRCH otherwise * Locks: none * References: *u1 and *u2 must not change during the call * u1 may equal u2, in which case only one reference is required */ int cr_canseeothergids(struct ucred *u1, struct ucred *u2) { int i, match; if (!see_other_gids) { match = 0; for (i = 0; i < u1->cr_ngroups; i++) { if (groupmember(u1->cr_groups[i], u2)) match = 1; if (match) break; } if (!match) { if (priv_check_cred(u1, PRIV_SEEOTHERGIDS) != 0) return (ESRCH); } } return (0); } /* * 'see_jail_proc' determines whether or not visibility of processes and * sockets with credentials holding different jail ids is possible using a * variety of system MIBs. * * XXX: data declarations should be together near the beginning of the file. */ static int see_jail_proc = 1; SYSCTL_INT(_security_bsd, OID_AUTO, see_jail_proc, CTLFLAG_RW, &see_jail_proc, 0, "Unprivileged processes may see subjects/objects with different jail ids"); /*- * Determine if u1 "can see" the subject specified by u2, according to the * 'see_jail_proc' policy. * Returns: 0 for permitted, ESRCH otherwise * Locks: none * References: *u1 and *u2 must not change during the call * u1 may equal u2, in which case only one reference is required */ int cr_canseejailproc(struct ucred *u1, struct ucred *u2) { if (u1->cr_uid == 0) return (0); return (!see_jail_proc && u1->cr_prison != u2->cr_prison ? ESRCH : 0); } /*- * Determine if u1 "can see" the subject specified by u2. * Returns: 0 for permitted, an errno value otherwise * Locks: none * References: *u1 and *u2 must not change during the call * u1 may equal u2, in which case only one reference is required */ int cr_cansee(struct ucred *u1, struct ucred *u2) { int error; if ((error = prison_check(u1, u2))) return (error); #ifdef MAC if ((error = mac_cred_check_visible(u1, u2))) return (error); #endif if ((error = cr_canseeotheruids(u1, u2))) return (error); if ((error = cr_canseeothergids(u1, u2))) return (error); if ((error = cr_canseejailproc(u1, u2))) return (error); return (0); } /*- * Determine if td "can see" the subject specified by p. * Returns: 0 for permitted, an errno value otherwise * Locks: Sufficient locks to protect p->p_ucred must be held. td really * should be curthread. * References: td and p must be valid for the lifetime of the call */ int p_cansee(struct thread *td, struct proc *p) { /* Wrap cr_cansee() for all functionality. */ KASSERT(td == curthread, ("%s: td not curthread", __func__)); PROC_LOCK_ASSERT(p, MA_OWNED); return (cr_cansee(td->td_ucred, p->p_ucred)); } /* * 'conservative_signals' prevents the delivery of a broad class of * signals by unprivileged processes to processes that have changed their * credentials since the last invocation of execve(). This can prevent * the leakage of cached information or retained privileges as a result * of a common class of signal-related vulnerabilities. However, this * may interfere with some applications that expect to be able to * deliver these signals to peer processes after having given up * privilege. */ static int conservative_signals = 1; SYSCTL_INT(_security_bsd, OID_AUTO, conservative_signals, CTLFLAG_RW, &conservative_signals, 0, "Unprivileged processes prevented from " "sending certain signals to processes whose credentials have changed"); /*- * Determine whether cred may deliver the specified signal to proc. * Returns: 0 for permitted, an errno value otherwise. * Locks: A lock must be held for proc. * References: cred and proc must be valid for the lifetime of the call. */ int cr_cansignal(struct ucred *cred, struct proc *proc, int signum) { int error; PROC_LOCK_ASSERT(proc, MA_OWNED); /* * Jail semantics limit the scope of signalling to proc in the * same jail as cred, if cred is in jail. */ error = prison_check(cred, proc->p_ucred); if (error) return (error); #ifdef MAC if ((error = mac_proc_check_signal(cred, proc, signum))) return (error); #endif if ((error = cr_canseeotheruids(cred, proc->p_ucred))) return (error); if ((error = cr_canseeothergids(cred, proc->p_ucred))) return (error); /* * UNIX signal semantics depend on the status of the P_SUGID * bit on the target process. If the bit is set, then additional * restrictions are placed on the set of available signals. */ if (conservative_signals && (proc->p_flag & P_SUGID)) { switch (signum) { case 0: case SIGKILL: case SIGINT: case SIGTERM: case SIGALRM: case SIGSTOP: case SIGTTIN: case SIGTTOU: case SIGTSTP: case SIGHUP: case SIGUSR1: case SIGUSR2: /* * Generally, permit job and terminal control * signals. */ break; default: /* Not permitted without privilege. */ error = priv_check_cred(cred, PRIV_SIGNAL_SUGID); if (error) return (error); } } /* * Generally, the target credential's ruid or svuid must match the * subject credential's ruid or euid. */ if (cred->cr_ruid != proc->p_ucred->cr_ruid && cred->cr_ruid != proc->p_ucred->cr_svuid && cred->cr_uid != proc->p_ucred->cr_ruid && cred->cr_uid != proc->p_ucred->cr_svuid) { error = priv_check_cred(cred, PRIV_SIGNAL_DIFFCRED); if (error) return (error); } return (0); } /*- * Determine whether td may deliver the specified signal to p. * Returns: 0 for permitted, an errno value otherwise * Locks: Sufficient locks to protect various components of td and p * must be held. td must be curthread, and a lock must be * held for p. * References: td and p must be valid for the lifetime of the call */ int p_cansignal(struct thread *td, struct proc *p, int signum) { KASSERT(td == curthread, ("%s: td not curthread", __func__)); PROC_LOCK_ASSERT(p, MA_OWNED); if (td->td_proc == p) return (0); /* * UNIX signalling semantics require that processes in the same * session always be able to deliver SIGCONT to one another, * overriding the remaining protections. */ /* XXX: This will require an additional lock of some sort. */ if (signum == SIGCONT && td->td_proc->p_session == p->p_session) return (0); /* * Some compat layers use SIGTHR and higher signals for * communication between different kernel threads of the same * process, so that they expect that it's always possible to * deliver them, even for suid applications where cr_cansignal() can * deny such ability for security consideration. It should be * pretty safe to do since the only way to create two processes * with the same p_leader is via rfork(2). */ if (td->td_proc->p_leader != NULL && signum >= SIGTHR && signum < SIGTHR + 4 && td->td_proc->p_leader == p->p_leader) return (0); return (cr_cansignal(td->td_ucred, p, signum)); } /*- * Determine whether td may reschedule p. * Returns: 0 for permitted, an errno value otherwise * Locks: Sufficient locks to protect various components of td and p * must be held. td must be curthread, and a lock must * be held for p. * References: td and p must be valid for the lifetime of the call */ int p_cansched(struct thread *td, struct proc *p) { int error; KASSERT(td == curthread, ("%s: td not curthread", __func__)); PROC_LOCK_ASSERT(p, MA_OWNED); if (td->td_proc == p) return (0); if ((error = prison_check(td->td_ucred, p->p_ucred))) return (error); #ifdef MAC if ((error = mac_proc_check_sched(td->td_ucred, p))) return (error); #endif if ((error = cr_canseeotheruids(td->td_ucred, p->p_ucred))) return (error); if ((error = cr_canseeothergids(td->td_ucred, p->p_ucred))) return (error); if (td->td_ucred->cr_ruid != p->p_ucred->cr_ruid && td->td_ucred->cr_uid != p->p_ucred->cr_ruid) { error = priv_check(td, PRIV_SCHED_DIFFCRED); if (error) return (error); } return (0); } /* * Handle getting or setting the prison's unprivileged_proc_debug * value. */ static int sysctl_unprivileged_proc_debug(SYSCTL_HANDLER_ARGS) { struct prison *pr; int error, val; val = prison_allow(req->td->td_ucred, PR_ALLOW_UNPRIV_DEBUG) != 0; error = sysctl_handle_int(oidp, &val, 0, req); if (error != 0 || req->newptr == NULL) return (error); pr = req->td->td_ucred->cr_prison; mtx_lock(&pr->pr_mtx); switch (val) { case 0: pr->pr_allow &= ~(PR_ALLOW_UNPRIV_DEBUG); break; case 1: pr->pr_allow |= PR_ALLOW_UNPRIV_DEBUG; break; default: error = EINVAL; } mtx_unlock(&pr->pr_mtx); return (error); } /* * The 'unprivileged_proc_debug' flag may be used to disable a variety of * unprivileged inter-process debugging services, including some procfs * functionality, ptrace(), and ktrace(). In the past, inter-process * debugging has been involved in a variety of security problems, and sites * not requiring the service might choose to disable it when hardening * systems. */ SYSCTL_PROC(_security_bsd, OID_AUTO, unprivileged_proc_debug, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_SECURE | CTLFLAG_MPSAFE, 0, 0, sysctl_unprivileged_proc_debug, "I", "Unprivileged processes may use process debugging facilities"); /*- * Determine whether td may debug p. * Returns: 0 for permitted, an errno value otherwise * Locks: Sufficient locks to protect various components of td and p * must be held. td must be curthread, and a lock must * be held for p. * References: td and p must be valid for the lifetime of the call */ int p_candebug(struct thread *td, struct proc *p) { int credentialchanged, error, grpsubset, i, uidsubset; KASSERT(td == curthread, ("%s: td not curthread", __func__)); PROC_LOCK_ASSERT(p, MA_OWNED); if ((error = priv_check(td, PRIV_DEBUG_UNPRIV))) return (error); if (td->td_proc == p) return (0); if ((error = prison_check(td->td_ucred, p->p_ucred))) return (error); #ifdef MAC if ((error = mac_proc_check_debug(td->td_ucred, p))) return (error); #endif if ((error = cr_canseeotheruids(td->td_ucred, p->p_ucred))) return (error); if ((error = cr_canseeothergids(td->td_ucred, p->p_ucred))) return (error); /* * Is p's group set a subset of td's effective group set? This * includes p's egid, group access list, rgid, and svgid. */ grpsubset = 1; for (i = 0; i < p->p_ucred->cr_ngroups; i++) { if (!groupmember(p->p_ucred->cr_groups[i], td->td_ucred)) { grpsubset = 0; break; } } grpsubset = grpsubset && groupmember(p->p_ucred->cr_rgid, td->td_ucred) && groupmember(p->p_ucred->cr_svgid, td->td_ucred); /* * Are the uids present in p's credential equal to td's * effective uid? This includes p's euid, svuid, and ruid. */ uidsubset = (td->td_ucred->cr_uid == p->p_ucred->cr_uid && td->td_ucred->cr_uid == p->p_ucred->cr_svuid && td->td_ucred->cr_uid == p->p_ucred->cr_ruid); /* * Has the credential of the process changed since the last exec()? */ credentialchanged = (p->p_flag & P_SUGID); /* * If p's gids aren't a subset, or the uids aren't a subset, * or the credential has changed, require appropriate privilege * for td to debug p. */ if (!grpsubset || !uidsubset) { error = priv_check(td, PRIV_DEBUG_DIFFCRED); if (error) return (error); } if (credentialchanged) { error = priv_check(td, PRIV_DEBUG_SUGID); if (error) return (error); } /* Can't trace init when securelevel > 0. */ if (p == initproc) { error = securelevel_gt(td->td_ucred, 0); if (error) return (error); } /* * Can't trace a process that's currently exec'ing. * * XXX: Note, this is not a security policy decision, it's a * basic correctness/functionality decision. Therefore, this check * should be moved to the caller's of p_candebug(). */ if ((p->p_flag & P_INEXEC) != 0) return (EBUSY); /* Denied explicitely */ if ((p->p_flag2 & P2_NOTRACE) != 0) { error = priv_check(td, PRIV_DEBUG_DENIED); if (error != 0) return (error); } return (0); } /*- * Determine whether the subject represented by cred can "see" a socket. * Returns: 0 for permitted, ENOENT otherwise. */ int cr_canseesocket(struct ucred *cred, struct socket *so) { int error; error = prison_check(cred, so->so_cred); if (error) return (ENOENT); #ifdef MAC error = mac_socket_check_visible(cred, so); if (error) return (error); #endif if (cr_canseeotheruids(cred, so->so_cred)) return (ENOENT); if (cr_canseeothergids(cred, so->so_cred)) return (ENOENT); return (0); } /*- * Determine whether td can wait for the exit of p. * Returns: 0 for permitted, an errno value otherwise * Locks: Sufficient locks to protect various components of td and p * must be held. td must be curthread, and a lock must * be held for p. * References: td and p must be valid for the lifetime of the call */ int p_canwait(struct thread *td, struct proc *p) { int error; KASSERT(td == curthread, ("%s: td not curthread", __func__)); PROC_LOCK_ASSERT(p, MA_OWNED); if ((error = prison_check(td->td_ucred, p->p_ucred))) return (error); #ifdef MAC if ((error = mac_proc_check_wait(td->td_ucred, p))) return (error); #endif #if 0 /* XXXMAC: This could have odd effects on some shells. */ if ((error = cr_canseeotheruids(td->td_ucred, p->p_ucred))) return (error); #endif return (0); } /* * Allocate a zeroed cred structure. */ struct ucred * crget(void) { struct ucred *cr; cr = malloc(sizeof(*cr), M_CRED, M_WAITOK | M_ZERO); refcount_init(&cr->cr_ref, 1); #ifdef AUDIT audit_cred_init(cr); #endif #ifdef MAC mac_cred_init(cr); #endif cr->cr_groups = cr->cr_smallgroups; cr->cr_agroups = sizeof(cr->cr_smallgroups) / sizeof(cr->cr_smallgroups[0]); return (cr); } /* * Claim another reference to a ucred structure. */ struct ucred * crhold(struct ucred *cr) { refcount_acquire(&cr->cr_ref); return (cr); } /* * Free a cred structure. Throws away space when ref count gets to 0. */ void crfree(struct ucred *cr) { KASSERT(cr->cr_ref > 0, ("bad ucred refcount: %d", cr->cr_ref)); KASSERT(cr->cr_ref != 0xdeadc0de, ("dangling reference to ucred")); if (refcount_release(&cr->cr_ref)) { /* * Some callers of crget(), such as nfs_statfs(), * allocate a temporary credential, but don't * allocate a uidinfo structure. */ if (cr->cr_uidinfo != NULL) uifree(cr->cr_uidinfo); if (cr->cr_ruidinfo != NULL) uifree(cr->cr_ruidinfo); /* * Free a prison, if any. */ if (cr->cr_prison != NULL) prison_free(cr->cr_prison); if (cr->cr_loginclass != NULL) loginclass_free(cr->cr_loginclass); #ifdef AUDIT audit_cred_destroy(cr); #endif #ifdef MAC mac_cred_destroy(cr); #endif if (cr->cr_groups != cr->cr_smallgroups) free(cr->cr_groups, M_CRED); free(cr, M_CRED); } } /* * Copy a ucred's contents from a template. Does not block. */ void crcopy(struct ucred *dest, struct ucred *src) { KASSERT(dest->cr_ref == 1, ("crcopy of shared ucred")); bcopy(&src->cr_startcopy, &dest->cr_startcopy, (unsigned)((caddr_t)&src->cr_endcopy - (caddr_t)&src->cr_startcopy)); crsetgroups(dest, src->cr_ngroups, src->cr_groups); uihold(dest->cr_uidinfo); uihold(dest->cr_ruidinfo); prison_hold(dest->cr_prison); loginclass_hold(dest->cr_loginclass); #ifdef AUDIT audit_cred_copy(src, dest); #endif #ifdef MAC mac_cred_copy(src, dest); #endif } /* * Dup cred struct to a new held one. */ struct ucred * crdup(struct ucred *cr) { struct ucred *newcr; newcr = crget(); crcopy(newcr, cr); return (newcr); } /* * Fill in a struct xucred based on a struct ucred. */ void cru2x(struct ucred *cr, struct xucred *xcr) { int ngroups; bzero(xcr, sizeof(*xcr)); xcr->cr_version = XUCRED_VERSION; xcr->cr_uid = cr->cr_uid; ngroups = MIN(cr->cr_ngroups, XU_NGROUPS); xcr->cr_ngroups = ngroups; bcopy(cr->cr_groups, xcr->cr_groups, ngroups * sizeof(*cr->cr_groups)); } void cru2xt(struct thread *td, struct xucred *xcr) { cru2x(td->td_ucred, xcr); xcr->cr_pid = td->td_proc->p_pid; } /* * Set initial process credentials. * Callers are responsible for providing the reference for provided credentials. */ void proc_set_cred_init(struct proc *p, struct ucred *newcred) { p->p_ucred = newcred; } /* * Change process credentials. * Callers are responsible for providing the reference for passed credentials * and for freeing old ones. * * Process has to be locked except when it does not have credentials (as it * should not be visible just yet) or when newcred is NULL (as this can be * only used when the process is about to be freed, at which point it should * not be visible anymore). */ void proc_set_cred(struct proc *p, struct ucred *newcred) { MPASS(p->p_ucred != NULL); - if (newcred == NULL) - MPASS(p->p_state == PRS_ZOMBIE); - else - PROC_LOCK_ASSERT(p, MA_OWNED); - + PROC_LOCK_ASSERT(p, MA_OWNED); p->p_ucred = newcred; - if (newcred != NULL) - PROC_UPDATE_COW(p); + PROC_UPDATE_COW(p); +} + +void +proc_unset_cred(struct proc *p) +{ + struct ucred *cr; + + MPASS(p->p_state == PRS_ZOMBIE); + cr = p->p_ucred; + p->p_ucred = NULL; + crfree(cr); } struct ucred * crcopysafe(struct proc *p, struct ucred *cr) { struct ucred *oldcred; int groups; PROC_LOCK_ASSERT(p, MA_OWNED); oldcred = p->p_ucred; while (cr->cr_agroups < oldcred->cr_agroups) { groups = oldcred->cr_agroups; PROC_UNLOCK(p); crextend(cr, groups); PROC_LOCK(p); oldcred = p->p_ucred; } crcopy(cr, oldcred); return (oldcred); } /* * Extend the passed in credential to hold n items. */ void crextend(struct ucred *cr, int n) { int cnt; /* Truncate? */ if (n <= cr->cr_agroups) return; /* * We extend by 2 each time since we're using a power of two * allocator until we need enough groups to fill a page. * Once we're allocating multiple pages, only allocate as many * as we actually need. The case of processes needing a * non-power of two number of pages seems more likely than * a real world process that adds thousands of groups one at a * time. */ if ( n < PAGE_SIZE / sizeof(gid_t) ) { if (cr->cr_agroups == 0) cnt = MAX(1, MINALLOCSIZE / sizeof(gid_t)); else cnt = cr->cr_agroups * 2; while (cnt < n) cnt *= 2; } else cnt = roundup2(n, PAGE_SIZE / sizeof(gid_t)); /* Free the old array. */ if (cr->cr_groups != cr->cr_smallgroups) free(cr->cr_groups, M_CRED); cr->cr_groups = malloc(cnt * sizeof(gid_t), M_CRED, M_WAITOK | M_ZERO); cr->cr_agroups = cnt; } /* * Copy groups in to a credential, preserving any necessary invariants. * Currently this includes the sorting of all supplemental gids. * crextend() must have been called before hand to ensure sufficient * space is available. */ static void crsetgroups_locked(struct ucred *cr, int ngrp, gid_t *groups) { int i; int j; gid_t g; KASSERT(cr->cr_agroups >= ngrp, ("cr_ngroups is too small")); bcopy(groups, cr->cr_groups, ngrp * sizeof(gid_t)); cr->cr_ngroups = ngrp; /* * Sort all groups except cr_groups[0] to allow groupmember to * perform a binary search. * * XXX: If large numbers of groups become common this should * be replaced with shell sort like linux uses or possibly * heap sort. */ for (i = 2; i < ngrp; i++) { g = cr->cr_groups[i]; for (j = i-1; j >= 1 && g < cr->cr_groups[j]; j--) cr->cr_groups[j + 1] = cr->cr_groups[j]; cr->cr_groups[j + 1] = g; } } /* * Copy groups in to a credential after expanding it if required. * Truncate the list to (ngroups_max + 1) if it is too large. */ void crsetgroups(struct ucred *cr, int ngrp, gid_t *groups) { if (ngrp > ngroups_max + 1) ngrp = ngroups_max + 1; crextend(cr, ngrp); crsetgroups_locked(cr, ngrp, groups); } /* * Get login name, if available. */ #ifndef _SYS_SYSPROTO_H_ struct getlogin_args { char *namebuf; u_int namelen; }; #endif /* ARGSUSED */ int sys_getlogin(struct thread *td, struct getlogin_args *uap) { char login[MAXLOGNAME]; struct proc *p = td->td_proc; size_t len; if (uap->namelen > MAXLOGNAME) uap->namelen = MAXLOGNAME; PROC_LOCK(p); SESS_LOCK(p->p_session); len = strlcpy(login, p->p_session->s_login, uap->namelen) + 1; SESS_UNLOCK(p->p_session); PROC_UNLOCK(p); if (len > uap->namelen) return (ERANGE); return (copyout(login, uap->namebuf, len)); } /* * Set login name. */ #ifndef _SYS_SYSPROTO_H_ struct setlogin_args { char *namebuf; }; #endif /* ARGSUSED */ int sys_setlogin(struct thread *td, struct setlogin_args *uap) { struct proc *p = td->td_proc; int error; char logintmp[MAXLOGNAME]; CTASSERT(sizeof(p->p_session->s_login) >= sizeof(logintmp)); error = priv_check(td, PRIV_PROC_SETLOGIN); if (error) return (error); error = copyinstr(uap->namebuf, logintmp, sizeof(logintmp), NULL); if (error != 0) { if (error == ENAMETOOLONG) error = EINVAL; return (error); } AUDIT_ARG_LOGIN(logintmp); PROC_LOCK(p); SESS_LOCK(p->p_session); strcpy(p->p_session->s_login, logintmp); SESS_UNLOCK(p->p_session); PROC_UNLOCK(p); return (0); } void setsugid(struct proc *p) { PROC_LOCK_ASSERT(p, MA_OWNED); p->p_flag |= P_SUGID; } /*- * Change a process's effective uid. * Side effects: newcred->cr_uid and newcred->cr_uidinfo will be modified. * References: newcred must be an exclusive credential reference for the * duration of the call. */ void change_euid(struct ucred *newcred, struct uidinfo *euip) { newcred->cr_uid = euip->ui_uid; uihold(euip); uifree(newcred->cr_uidinfo); newcred->cr_uidinfo = euip; } /*- * Change a process's effective gid. * Side effects: newcred->cr_gid will be modified. * References: newcred must be an exclusive credential reference for the * duration of the call. */ void change_egid(struct ucred *newcred, gid_t egid) { newcred->cr_groups[0] = egid; } /*- * Change a process's real uid. * Side effects: newcred->cr_ruid will be updated, newcred->cr_ruidinfo * will be updated, and the old and new cr_ruidinfo proc * counts will be updated. * References: newcred must be an exclusive credential reference for the * duration of the call. */ void change_ruid(struct ucred *newcred, struct uidinfo *ruip) { (void)chgproccnt(newcred->cr_ruidinfo, -1, 0); newcred->cr_ruid = ruip->ui_uid; uihold(ruip); uifree(newcred->cr_ruidinfo); newcred->cr_ruidinfo = ruip; (void)chgproccnt(newcred->cr_ruidinfo, 1, 0); } /*- * Change a process's real gid. * Side effects: newcred->cr_rgid will be updated. * References: newcred must be an exclusive credential reference for the * duration of the call. */ void change_rgid(struct ucred *newcred, gid_t rgid) { newcred->cr_rgid = rgid; } /*- * Change a process's saved uid. * Side effects: newcred->cr_svuid will be updated. * References: newcred must be an exclusive credential reference for the * duration of the call. */ void change_svuid(struct ucred *newcred, uid_t svuid) { newcred->cr_svuid = svuid; } /*- * Change a process's saved gid. * Side effects: newcred->cr_svgid will be updated. * References: newcred must be an exclusive credential reference for the * duration of the call. */ void change_svgid(struct ucred *newcred, gid_t svgid) { newcred->cr_svgid = svgid; } diff --git a/sys/sys/ucred.h b/sys/sys/ucred.h index 43849aac76b8..e4843c336c59 100644 --- a/sys/sys/ucred.h +++ b/sys/sys/ucred.h @@ -1,125 +1,126 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 1989, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)ucred.h 8.4 (Berkeley) 1/9/95 * $FreeBSD$ */ #ifndef _SYS_UCRED_H_ #define _SYS_UCRED_H_ #include struct loginclass; #define XU_NGROUPS 16 /* * Credentials. * * Please do not inspect cr_uid directly to determine superuserness. The * priv(9) interface should be used to check for privilege. */ #if defined(_KERNEL) || defined(_WANT_UCRED) struct ucred { u_int cr_ref; /* reference count */ #define cr_startcopy cr_uid uid_t cr_uid; /* effective user id */ uid_t cr_ruid; /* real user id */ uid_t cr_svuid; /* saved user id */ int cr_ngroups; /* number of groups */ gid_t cr_rgid; /* real group id */ gid_t cr_svgid; /* saved group id */ struct uidinfo *cr_uidinfo; /* per euid resource consumption */ struct uidinfo *cr_ruidinfo; /* per ruid resource consumption */ struct prison *cr_prison; /* jail(2) */ struct loginclass *cr_loginclass; /* login class */ u_int cr_flags; /* credential flags */ void *cr_pspare2[2]; /* general use 2 */ #define cr_endcopy cr_label struct label *cr_label; /* MAC label */ struct auditinfo_addr cr_audit; /* Audit properties. */ gid_t *cr_groups; /* groups */ int cr_agroups; /* Available groups */ gid_t cr_smallgroups[XU_NGROUPS]; /* storage for small groups */ }; #define NOCRED ((struct ucred *)0) /* no credential available */ #define FSCRED ((struct ucred *)-1) /* filesystem credential */ #endif /* _KERNEL || _WANT_UCRED */ /* * Flags for cr_flags. */ #define CRED_FLAG_CAPMODE 0x00000001 /* In capability mode. */ /* * This is the external representation of struct ucred. */ struct xucred { u_int cr_version; /* structure layout version */ uid_t cr_uid; /* effective user id */ short cr_ngroups; /* number of groups */ gid_t cr_groups[XU_NGROUPS]; /* groups */ union { void *_cr_unused1; /* compatibility with old ucred */ pid_t cr_pid; }; }; #define XUCRED_VERSION 0 /* This can be used for both ucred and xucred structures. */ #define cr_gid cr_groups[0] #ifdef _KERNEL struct proc; struct thread; void change_egid(struct ucred *newcred, gid_t egid); void change_euid(struct ucred *newcred, struct uidinfo *euip); void change_rgid(struct ucred *newcred, gid_t rgid); void change_ruid(struct ucred *newcred, struct uidinfo *ruip); void change_svgid(struct ucred *newcred, gid_t svgid); void change_svuid(struct ucred *newcred, uid_t svuid); void crcopy(struct ucred *dest, struct ucred *src); struct ucred *crcopysafe(struct proc *p, struct ucred *cr); struct ucred *crdup(struct ucred *cr); void crextend(struct ucred *cr, int n); void proc_set_cred_init(struct proc *p, struct ucred *cr); void proc_set_cred(struct proc *p, struct ucred *cr); +void proc_unset_cred(struct proc *p); void crfree(struct ucred *cr); struct ucred *crget(void); struct ucred *crhold(struct ucred *cr); void cru2x(struct ucred *cr, struct xucred *xcr); void cru2xt(struct thread *td, struct xucred *xcr); void crsetgroups(struct ucred *cr, int n, gid_t *groups); int groupmember(gid_t gid, struct ucred *cred); #endif /* _KERNEL */ #endif /* !_SYS_UCRED_H_ */