[PATCH 5.4 097/102] block: fix memleak of bio integrity data

Greg Kroah-Hartman
2020-01-24T09:43:11Z

From: Justin Tee <justin.tee@broadcom.com>

[ Upstream commit ece841abbed2da71fa10710c687c9ce9efb6bf69 ]

7c20f11680a4 ("bio-integrity: stop abusing bi_end_io") moves
bio_integrity_free from bio_uninit() to bio_integrity_verify_fn()
and bio_endio(). This way looks wrong because bio may be freed
without calling bio_endio(), for example, blk_rq_unprep_clone() is
called from dm_mq_queue_rq() when the underlying queue of dm-mpath
is busy.

So memory leak of bio integrity data is caused by commit 7c20f11680a4.

Fixes this issue by re-adding bio_integrity_free() to bio_uninit().

Fixes: 7c20f11680a4 ("bio-integrity: stop abusing bi_end_io")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by Justin Tee <justin.tee@broadcom.com>

Add commit log, and simplify/fix the original patch wroten by Justin.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
block/bio-integrity.c | 2 +-
block/bio.c | 3 +++
block/blk.h | 4 ++++
3 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/block/bio-integrity.c b/block/bio-integrity.c
index fb95dbb21dd88..bf62c25cde8f4 100644
--- a/block/bio-integrity.c
+++ b/block/bio-integrity.c
@@ -87,7 +87,7 @@ EXPORT_SYMBOL(bio_integrity_alloc);
* Description: Used to free the integrity portion of a bio. Usually
* called from bio_free().
*/
-static void bio_integrity_free(struct bio *bio)
+void bio_integrity_free(struct bio *bio)
{
struct bio_integrity_payload *bip = bio_integrity(bio);
struct bio_set *bs = bio->bi_pool;
diff --git a/block/bio.c b/block/bio.c
index 906da3581a3e8..94d697217887a 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -233,6 +233,9 @@ fallback:
void bio_uninit(struct bio *bio)
{
bio_disassociate_blkg(bio);
+
+ if (bio_integrity(bio))
+ bio_integrity_free(bio);
}
EXPORT_SYMBOL(bio_uninit);

diff --git a/block/blk.h b/block/blk.h
index ffea1691470e6..ee3d5664d9627 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -122,6 +122,7 @@ static inline void blk_rq_bio_prep(struct request *rq, struct bio *bio,
#ifdef CONFIG_BLK_DEV_INTEGRITY
void blk_flush_integrity(void);
bool __bio_integrity_endio(struct bio *);
+void bio_integrity_free(struct bio *bio);
static inline bool bio_integrity_endio(struct bio *bio)
{
if (bio_integrity(bio))
@@ -167,6 +168,9 @@ static inline bool bio_integrity_endio(struct bio *bio)
{
return true;
}
+static inline void bio_integrity_free(struct bio *bio)
+{
+}
#endif /* CONFIG_BLK_DEV_INTEGRITY */

unsigned long blk_rq_timeout(unsigned long timeout);
--
2.20.1