From: Mikulas Patocka <mpatocka@redhat.com> commit 08c1af8f1c13bbf210f1760132f4df24d0ed46d6 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Yuntao Liu <liuyuntao12@huawei.com> --- drivers/md/dm-integrity.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c index 66016ce253ce..db09e8748ec8 100644 --- a/drivers/md/dm-integrity.c +++ b/drivers/md/dm-integrity.c @@ -3509,6 +3509,7 @@ static int dm_integrity_ctr(struct dm_target *ti, unsigned argc, char **argv) } if (ic->sb->flags & cpu_to_le32(SB_FLAG_RECALCULATING)) { + size_t recalc_tags_size; if (!ic->internal_hash) { r = -EINVAL; ti->error = "Recalculate is only valid with internal hash"; @@ -3527,8 +3528,10 @@ static int dm_integrity_ctr(struct dm_target *ti, unsigned argc, char **argv) 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; -- 2.34.1