diff options
| author | Mikulas Patocka <mpatocka@redhat.com> | 2022-06-16 13:21:27 -0400 |
|---|---|---|
| committer | Mike Snitzer <snitzer@kernel.org> | 2022-06-16 19:38:49 -0400 |
| commit | 5d7362d0d56da3b85b19b5e5ce657026c2eef479 (patch) | |
| tree | cd80ec66ee3d3574d43c72f77a5185ff85e366dd /drivers/md/dm.c | |
| parent | 10eb3a0d517fcc83eeea4242c149461205675eb4 (diff) | |
dm: fix use-after-free in dm_put_live_table_bio
dm_put_live_table_bio is called from the end of dm_submit_bio.
However, at this point, the bio may be already finished and the caller
may have freed the bio. Consequently, dm_put_live_table_bio accesses
the stale "bio" pointer.
Fix this bug by loading the bi_opf value and passing it to
dm_get_live_table_bio and dm_put_live_table_bio instead of the bio.
This bug was found by running the lvm2 testsuite with kasan.
Fixes: 563a225c9fd2 ("dm: introduce dm_{get,put}_live_table_bio called from dm_submit_bio")
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Diffstat (limited to 'drivers/md/dm.c')
| -rw-r--r-- | drivers/md/dm.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c index d5e6d33700e5..6ea14ab94aa6 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -715,18 +715,18 @@ static void dm_put_live_table_fast(struct mapped_device *md) __releases(RCU) } static inline struct dm_table *dm_get_live_table_bio(struct mapped_device *md, - int *srcu_idx, struct bio *bio) + int *srcu_idx, unsigned bio_opf) { - if (bio->bi_opf & REQ_NOWAIT) + if (bio_opf & REQ_NOWAIT) return dm_get_live_table_fast(md); else return dm_get_live_table(md, srcu_idx); } static inline void dm_put_live_table_bio(struct mapped_device *md, int srcu_idx, - struct bio *bio) + unsigned bio_opf) { - if (bio->bi_opf & REQ_NOWAIT) + if (bio_opf & REQ_NOWAIT) dm_put_live_table_fast(md); else dm_put_live_table(md, srcu_idx); @@ -1715,8 +1715,9 @@ static void dm_submit_bio(struct bio *bio) struct mapped_device *md = bio->bi_bdev->bd_disk->private_data; int srcu_idx; struct dm_table *map; + unsigned bio_opf = bio->bi_opf; - map = dm_get_live_table_bio(md, &srcu_idx, bio); + map = dm_get_live_table_bio(md, &srcu_idx, bio_opf); /* If suspended, or map not yet available, queue this IO for later */ if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) || @@ -1732,7 +1733,7 @@ static void dm_submit_bio(struct bio *bio) dm_split_and_process_bio(md, map, bio); out: - dm_put_live_table_bio(md, srcu_idx, bio); + dm_put_live_table_bio(md, srcu_idx, bio_opf); } static bool dm_poll_dm_io(struct dm_io *io, struct io_comp_batch *iob, |