diff options
| author | Mikulas Patocka <mpatocka@redhat.com> | 2023-12-05 16:39:16 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-01-08 11:27:37 +0100 |
| commit | 8e2a03614d0fd73f72cffdd26c766b8a65431a56 (patch) | |
| tree | ec8207bbb59576693b5f111590a589e68a37455b | |
| parent | 89b6ae907c6bcc175bc95a67d6936217530a29ff (diff) | |
dm-integrity: don't modify bio's immutable bio_vec in integrity_metadata()
commit b86f4b790c998afdbc88fe1aa55cfe89c4068726 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: 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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/md/dm-integrity.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c index 234464c1c050..a884fcf65063 100644 --- a/drivers/md/dm-integrity.c +++ b/drivers/md/dm-integrity.c @@ -1379,11 +1379,12 @@ static void integrity_metadata(struct work_struct *w) checksums = checksums_onstack; __bio_for_each_segment(bv, bio, iter, dio->bio_details.bi_iter) { + struct bio_vec bv_copy = bv; unsigned pos; char *mem, *checksums_ptr; again: - mem = (char *)kmap_atomic(bv.bv_page) + bv.bv_offset; + mem = (char *)kmap_atomic(bv_copy.bv_page) + bv_copy.bv_offset; pos = 0; checksums_ptr = checksums; do { @@ -1392,7 +1393,7 @@ again: 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_atomic(mem); r = dm_integrity_rw_tag(ic, checksums, &dio->metadata_block, &dio->metadata_offset, @@ -1412,9 +1413,9 @@ again: 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; } } |