From: Jens Axboe <axboe@xxxxxxxxx>
[ Upstream commit 605f7415ecfb426610195dd6c7577b30592b3369 ]
Most of bioset_exit() is fine being called twice, as it clears the
various allocations etc when they are freed. The exception is
bio_alloc_cache_destroy(), which does not clear ->cache when it has
freed it.
This isn't necessarily a bug, but can be if buggy users does call the
exit path more then once, or with just a memset() bioset which has
never been initialized. dm appears to be one such user.
Fixes: be4d234d7aeb ("bio: add allocation cache abstraction")
Link: https://lore.kernel.org/linux-block/YpK7m+14A+pZKs5k@xxxxxxxxxxxxxxxxxxxx/
Reported-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
block/bio.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/block/bio.c b/block/bio.c
index 738fea03edbf..dc6940621d7d 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -668,6 +668,7 @@ static void bio_alloc_cache_destroy(struct bio_set *bs)
bio_alloc_cache_prune(cache, -1U);
}
free_percpu(bs->cache);
+ bs->cache = NULL;
}
/**
--
2.35.1
