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Re: CVE request: kernel: Unused iocbs in a batch should not be accounted as active
From: Kurt Seifried <kseifried () redhat com>
Date: Tue, 17 Jan 2012 22:34:52 -0700
On 01/17/2012 10:30 PM, Eugene Teo wrote:
Author: Gleb Natapov <gleb () redhat com>
Date: Sun Jan 8 17:07:28 2012 +0200
Unused iocbs in a batch should not be accounted as active.
Since commit 080d676de095 ("aio: allocate kiocbs in batches") iocbs
are allocated in a batch during processing of first iocbs. All iocbs in
a batch are automatically added to ctx->active_reqs list and accounted
If one (not the last one) of iocbs submitted by an user fails,
further iocbs are not processed, but they are still present in
ctx->active_reqs and accounted in ctx->reqs_active. This causes process
to stuck in a D state in wait_for_all_aios() on exit since
ctx->reqs_active will never go down to zero. Furthermore since
kiocb_batch_free() frees iocb without removing it from active_reqs list
the list become corrupted which may cause oops.
Fix this by removing iocb from ctx->active_reqs and updating
ctx->reqs_active in kiocb_batch_free().
Signed-off-by: Gleb Natapov <gleb () redhat com>
Reviewed-by: Jeff Moyer <jmoyer () redhat com>
Cc: stable () kernel org # 3.2
Signed-off-by: Linus Torvalds <torvalds () linux-foundation org>
Issue introduced in v3.2-rc1 via commit 080d676d.
Please use CVE-2012-0058 for this issue
-- Kurt Seifried / Red Hat Security Response Team