Right. False positive. Coverity doesn't grok sbuf memory management fully.
On Tue, Apr 26, 2016 at 11:22 AM, NGie Cooper <yaneurab...@gmail.com> wrote: > > > 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"
