dm-integrity: don't modify bio's immutable bio_vec in integrity_metadata()

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commit b86f4b790c upstream.

__bio_for_each_segment assumes that the first struct bio_vec argument
doesn't change - it calls "bio_advance_iter_single((bio), &(iter),
(bvl).bv_len)" to advance the iterator. Unfortunately, the dm-integrity
code changes the bio_vec with "bv.bv_len -= pos". When this code path
is taken, the iterator would be out of sync and dm-integrity would
report errors. This happens if the machine is out of memory and
"kmalloc" fails.

Fix this bug by making a copy of "bv" and changing the copy instead.

Fixes: 7eada909bf ("dm: add integrity target")
Cc: stable@vger.kernel.org	# v4.12+
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

...

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Mikulas Patocka 2023-12-05 16:39:16 +01:00 • committed by Greg Kroah-Hartman

parent 33b976a0f2

commit 7f7efa30fa

1 changed files with 6 additions and 5 deletions

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drivers/md/dm-integrity.c

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