trasz retitled this revision from Fix Linux recvmsg(2) when msg_namelen returned is 0. Previously it would fail with EINVAL, breaking some of the Python regression tests. to Fix Linux recvmsg(2) when msg_namelen returned is 0.Jun 21 2020, 8:34 PM

trasz edited the summary of this revision. (Show Details)

trasz added a reviewer: Linux Emulation.

emaste added a subscriber: emaste.Jun 21 2020, 8:54 PM

emaste added inline comments.

sys/compat/linux/linux_socket.c
1202 ↗	(On Diff #73445)	what's msg_namelen's type?

trasz added inline comments.Jun 21 2020, 11:57 PM

sys/compat/linux/linux_socket.c
1202 ↗	(On Diff #73445)	It's socklen_t.

trasz added a reviewer: kib.Jun 22 2020, 1:10 PM

kib added inline comments.Jun 22 2020, 2:35 PM

sys/compat/linux/linux_socket.c
1188 ↗	(On Diff #73445)	Is it fine to not check msg_namelen there ?
1202 ↗	(On Diff #73445)	Fix the style while there, msg_name != NULL ?

emaste added inline comments.Jun 22 2020, 4:36 PM

sys/compat/linux/linux_socket.c
1202 ↗	(On Diff #73445)	should it be `> 0` not `!= 0`?

Fix various issues.

Harbormaster completed remote builds in B32018: Diff 73793.Jun 27 2020, 11:49 PM

trasz marked 2 inline comments as done.Jun 27 2020, 11:50 PM

trasz added inline comments.

sys/compat/linux/linux_socket.c
1202 ↗	(On Diff #73445)	Not sure if the check is needed, but better safe than sorry.

kib added inline comments.Jul 1 2020, 12:14 AM

sys/compat/linux/linux_socket.c
1189 ↗	(On Diff #73793)	Is msg_namelen user-controlled ? Does it allow for arbitrary-sized allocations controlled by user ?
1204 ↗	(On Diff #73793)	Isn't msg_namelen > 0 recheck is redundant ?

trasz added inline comments.Jul 1 2020, 11:04 AM

sys/compat/linux/linux_socket.c
1189 ↗	(On Diff #73793)	Hah, good catch!
1204 ↗	(On Diff #73793)	It isn't, that's the whole point of this change: kern_recvit() updates it. I guess I should add a comment about it.

Add comment explaining the second check, and cap the buffer size.

Harbormaster completed remote builds in B32127: Diff 74058.Jul 3 2020, 8:16 PM

(Tinderboxed.)

kib added inline comments.Jul 4 2020, 2:47 PM

sys/compat/linux/linux_socket.c
1219 ↗	(On Diff #74058)	What should the code do if msg->msg_name != NULL but msg->msg_namelen == 0 (after the kern_recvit()) ?

trasz added inline comments.Jul 4 2020, 5:57 PM

sys/compat/linux/linux_socket.c
1219 ↗	(On Diff #74058)	My guess is it should copyout the new length. But right now the code does not copyout the length in any case, and like previously, I prefer the small steps approach. I'll mention it in the commit message.