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sbappendcontrol() needs to avoid clearing M_NOTREADY on data mbufs.
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Authored by markj on Apr 7 2020, 9:53 PM.
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Details

Summary

If LOCAL_CREDS is set on a unix socket and we use sendfile, sendfile
will call uipc_send(PRUS_NOTREADY), which prepends a control message to
M_NOTREADY mbufs. uipc_send() then calls sbappendcontrol() instead of
sbappend(), and sbappendcontrol() was clearing M_NOTREADY, leading to
nasty results.

Test Plan

Ran a simple test case that previously triggers this bug and causes a kernel
panic due to an mbuf double free.

Diff Detail

Repository
rS FreeBSD src repository - subversion
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Event Timeline

markj added a reviewer: glebius.
This revision was not accepted when it landed; it landed in state Needs Review.Apr 10 2020, 8:42 PM
This revision was automatically updated to reflect the committed changes.