The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x b86f4b790c998afdbc88fe1aa55cfe89c4068726 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2023123001-profusely-reassign-059b@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:

b86f4b790c99 ("dm-integrity: don't modify bio's immutable bio_vec in integrity_metadata()") 86a3238c7b9b ("dm: change "unsigned" to "unsigned int"") 7533afa1d27b ("dm: send just one event on resize, not two") 5cd6d1d53a1f ("dm integrity: Remove bi_sector that's only used by commented debug code") 22c40e134c4c ("dm cache: Add some documentation to dm-cache-background-tracker.h") 86e4d3e8d183 ("dm-crypt: provide dma_alignment limit in io_hints") c3adefb5baf3 ("Merge tag 'for-6.0/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From b86f4b790c998afdbc88fe1aa55cfe89c4068726 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka mpatocka@redhat.com Date: Tue, 5 Dec 2023 16:39:16 +0100 Subject: [PATCH] dm-integrity: don't modify bio's immutable bio_vec in integrity_metadata()

__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: 7eada909bfd7 ("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

diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c index e85c688fd91e..c5f03aab4552 100644 --- a/drivers/md/dm-integrity.c +++ b/drivers/md/dm-integrity.c @@ -1755,11 +1755,12 @@ static void integrity_metadata(struct work_struct *w) sectors_to_process = dio->range.n_sectors;

__bio_for_each_segment(bv, bio, iter, dio->bio_details.bi_iter) { + struct bio_vec bv_copy = bv; unsigned int pos; char *mem, *checksums_ptr;

again: - mem = bvec_kmap_local(&bv); + mem = bvec_kmap_local(&bv_copy); pos = 0; checksums_ptr = checksums; do { @@ -1768,7 +1769,7 @@ static void integrity_metadata(struct work_struct *w) sectors_to_process -= ic->sectors_per_block; pos += ic->sectors_per_block << SECTOR_SHIFT; sector += ic->sectors_per_block; - } while (pos < bv.bv_len && sectors_to_process && checksums != checksums_onstack); + } while (pos < bv_copy.bv_len && sectors_to_process && checksums != checksums_onstack); kunmap_local(mem);

r = dm_integrity_rw_tag(ic, checksums, &dio->metadata_block, &dio->metadata_offset, @@ -1793,9 +1794,9 @@ static void integrity_metadata(struct work_struct *w) if (!sectors_to_process) break;

- if (unlikely(pos < bv.bv_len)) { - bv.bv_offset += pos; - bv.bv_len -= pos; + if (unlikely(pos < bv_copy.bv_len)) { + bv_copy.bv_offset += pos; + bv_copy.bv_len -= pos; goto again; } }