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authorNikos Tsironis <ntsironis@arrikto.com>2020-03-27 17:01:10 +0300
committerMike Snitzer <snitzer@redhat.com>2020-03-27 21:42:25 +0300
commit9fc06ff56845cc5ccafec52f545fc2e08d22f849 (patch)
treea1d17e2eba1e558cbcccf03d83ed817356a45d82 /drivers/md
parentcd481c12269b4d276f1a52eda0ebd419079bfe3a (diff)
downloadlinux-9fc06ff56845cc5ccafec52f545fc2e08d22f849.tar.xz
dm clone: Add missing casts to prevent overflows and data corruption
Add missing casts when converting from regions to sectors. In case BITS_PER_LONG == 32, the lack of the appropriate casts can lead to overflows and miscalculation of the device sector. As a result, we could end up discarding and/or copying the wrong parts of the device, thus corrupting the device's data. Fixes: 7431b7835f55 ("dm: add clone target") Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/dm-clone-target.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/drivers/md/dm-clone-target.c b/drivers/md/dm-clone-target.c
index 6ee85fb3388a..ca5020c58f7c 100644
--- a/drivers/md/dm-clone-target.c
+++ b/drivers/md/dm-clone-target.c
@@ -282,7 +282,7 @@ static bool bio_triggers_commit(struct clone *clone, struct bio *bio)
/* Get the address of the region in sectors */
static inline sector_t region_to_sector(struct clone *clone, unsigned long region_nr)
{
- return (region_nr << clone->region_shift);
+ return ((sector_t)region_nr << clone->region_shift);
}
/* Get the region number of the bio */
@@ -471,7 +471,7 @@ static void complete_discard_bio(struct clone *clone, struct bio *bio, bool succ
if (test_bit(DM_CLONE_DISCARD_PASSDOWN, &clone->flags) && success) {
remap_to_dest(clone, bio);
bio_region_range(clone, bio, &rs, &nr_regions);
- trim_bio(bio, rs << clone->region_shift,
+ trim_bio(bio, region_to_sector(clone, rs),
nr_regions << clone->region_shift);
generic_make_request(bio);
} else
@@ -804,11 +804,14 @@ static void hydration_copy(struct dm_clone_region_hydration *hd, unsigned int nr
struct dm_io_region from, to;
struct clone *clone = hd->clone;
+ if (WARN_ON(!nr_regions))
+ return;
+
region_size = clone->region_size;
region_start = hd->region_nr;
region_end = region_start + nr_regions - 1;
- total_size = (nr_regions - 1) << clone->region_shift;
+ total_size = region_to_sector(clone, nr_regions - 1);
if (region_end == clone->nr_regions - 1) {
/*