diff options
| author | Mikulas Patocka <mpatocka@redhat.com> | 2022-04-03 14:38:22 -0400 |
|---|---|---|
| committer | Mike Snitzer <snitzer@kernel.org> | 2022-04-13 12:38:49 -0400 |
| commit | 08c1af8f1c13bbf210f1760132f4df24d0ed46d6 (patch) | |
| tree | 676b1092df0ba94cb4452b1bdd1caafd7d70dcb0 /drivers | |
| parent | ce522ba9ef7e2d9fb22a39eb3371c0c64e2a433e (diff) | |
dm integrity: fix memory corruption when tag_size is less than digest size
It is possible to set up dm-integrity in such a way that the
"tag_size" parameter is less than the actual digest size. In this
situation, a part of the digest beyond tag_size is ignored.
In this case, dm-integrity would write beyond the end of the
ic->recalc_tags array and corrupt memory. The corruption happened in
integrity_recalc->integrity_sector_checksum->crypto_shash_final.
Fix this corruption by increasing the tags array so that it has enough
padding at the end to accomodate the loop in integrity_recalc() being
able to write a full digest size for the last member of the tags
array.
Cc: stable@vger.kernel.org # v4.19+
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/md/dm-integrity.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c index ad2d5faa2ebb..36ae30b73a6e 100644 --- a/drivers/md/dm-integrity.c +++ b/drivers/md/dm-integrity.c @@ -4399,6 +4399,7 @@ try_smaller_buffer: } if (ic->internal_hash) { + size_t recalc_tags_size; ic->recalc_wq = alloc_workqueue("dm-integrity-recalc", WQ_MEM_RECLAIM, 1); if (!ic->recalc_wq ) { ti->error = "Cannot allocate workqueue"; @@ -4412,8 +4413,10 @@ try_smaller_buffer: r = -ENOMEM; goto bad; } - ic->recalc_tags = kvmalloc_array(RECALC_SECTORS >> ic->sb->log2_sectors_per_block, - ic->tag_size, GFP_KERNEL); + recalc_tags_size = (RECALC_SECTORS >> ic->sb->log2_sectors_per_block) * ic->tag_size; + if (crypto_shash_digestsize(ic->internal_hash) > ic->tag_size) + recalc_tags_size += crypto_shash_digestsize(ic->internal_hash) - ic->tag_size; + ic->recalc_tags = kvmalloc(recalc_tags_size, GFP_KERNEL); if (!ic->recalc_tags) { ti->error = "Cannot allocate tags for recalculating"; r = -ENOMEM; |