> On Apr 26, 2016, at 11:03, Ulrich Spörlein <uspoerl...@gmail.com> wrote: > > 2016-04-25 10:06 GMT-07:00 Jamie Gritton <ja...@freebsd.org>: >> Author: jamie >> Date: Mon Apr 25 17:06:50 2016 >> New Revision: 298585 >> URL: https://svnweb.freebsd.org/changeset/base/298585 >> >> Log: >> Encapsulate SYSV IPC objects in jails. Define per-module parameters >> sysvmsg, sysvsem, and sysvshm, with the following bahavior: >> >> inherit: allow full access to the IPC primitives. This is the same as >> the current setup with allow.sysvipc is on. Jails and the base system >> can see (and moduly) each other's objects, which is generally considered >> a bad thing (though may be useful in some circumstances). >> >> disable: all no access, same as the current setup with allow.sysvipc off. >> >> new: A jail may see use the IPC objects that it has created. It also >> gets its own IPC key namespace, so different jails may have their own >> objects using the same key value. The parent jail (or base system) can >> see the jail's IPC objects, but not its keys. >> >> PR: 48471 >> Submitted by: based on work by kikucha...@gmail.com >> MFC after: 5 days >> >> Modified: >> head/sys/kern/sysv_msg.c >> head/sys/kern/sysv_sem.c >> head/sys/kern/sysv_shm.c >> head/usr.sbin/jail/jail.8 > > Looks like some bad sbuf_deletes, see the recent Coverity report (are > you folks getting these emails?) > > *** CID 1354974: Memory - corruptions (BAD_FREE) > /sys/kern/sysv_shm.c: 1043 in sysctl_shmsegs() > 1037 shmseg->u.shm_perm.key = IPC_PRIVATE; > 1038 } > 1039 > 1040 sbuf_bcat(&sb, shmseg, sizeof(*shmseg)); > 1041 } > 1042 error = sbuf_finish(&sb); >>>> CID 1354974: Memory - corruptions (BAD_FREE) >>>> "sbuf_delete" frees address of "sb". > 1043 sbuf_delete(&sb); > 1044 > 1045 done: > 1046 SYSVSHM_UNLOCK(); > 1047 return (error); > 1048 } > > ** CID 1354975: Memory - corruptions (BAD_FREE) > > and one in sysv_msg.c
cem and I hashed this out recently with ntb on phrabricator. The issue is that our sbuf implementation is "clever" and has different code paths for stack vs heap allocation -- this pattern is ok per stack allocation, but not heap allocation... Coverity only knows about how to instrument the latter. Thanks, -Ngie _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
