On 12/04/2011 02:11 AM, Stratos Psomadakis wrote: > On 12/03/2011 11:07 PM, Steffen Maier wrote: >> On 12/02/2011 04:26 PM, Stratos Psomadakis wrote: >>> After upstream commit 4e6c82b3614a18740ef63109d58743a359266daf ([SCSI] >>> fix WARNING: at drivers/scsi/scsi_lib.c:1704), which is also included in >>> 3.0-stable and 3.1-stable kernels, the kernel fails to boot (NULL >>> pointer dereference in sym53c8xx_slave_destroy). >>> >>> Bug report at the Gentoo Bugzilla (reported and bisected by Martin von >>> Gagern). [1] (stack trace [2]) >>> >>> I think that the problem is that (after commit 4e6c82b) >>> __scsi_remove_device() is called if slave_alloc() in scsi_alloc_sdev() >>> fails. But __scsi_remove_device() calls slave_destroy(), which (I think) >>> doesn't make much sense (ie to call slave_destroy() when slave_alloc() >>> fails). >>> >>> For sym53c8xx, this results in a NULL pointer dereference (struct >>> sym_lcb pointer) in slave_destroy(). >>> >>> [1] https://bugs.gentoo.org/show_bug.cgi?id=392567 >>> [2] https://392567.bugs.gentoo.org/attachment.cgi?id=294381 >> To me this looks like the same thing we encountered in the zfcp LLD: >> http://www.spinics.net/lists/linux-scsi/msg55575.html >> James explained the pairing of slave_alloc and slave_destroy even if >> slave_alloc returned early in which case slave_destroy needs to cope >> with that: >> http://www.spinics.net/lists/linux-scsi/msg55449.html >> > Indeed. > > I'll follow-up with a patch similar to the one you sent for zfcp. I > think that returning if sym_lcb is NULL should be ok. I forgot to chain the patch email in this thread, so here's the link: http://marc.info/?l=linux-scsi&m=132295936832641&w=2 >> HTH >> Steffen >> >> Linux on System z Development >> >> IBM Deutschland Research & Development GmbH >> Vorsitzender des Aufsichtsrats: Martin Jetter >> Geschäftsführung: Dirk Wittkopp >> Sitz der Gesellschaft: Böblingen >> Registergericht: Amtsgericht Stuttgart, HRB 243294 >> >> -- >> To unsubscribe from this list: send the line "unsubscribe >> linux-kernel" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> Please read the FAQ at http://www.tux.org/lkml/ -- Stratos Psomadakis <psomas@xxxxxxxxxx>
Attachment:
signature.asc
Description: OpenPGP digital signature
