| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.15 090/247] block: make bioset_exit() fully resilient against being called twice | Date | Mon, 13 Jun 2022 12:09:52 +0200 |
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From: Jens Axboe <axboe@kernel.dk>
[ 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@casper.infradead.org/ Reported-by: Matthew Wilcox <willy@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org> --- block/bio.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/block/bio.c b/block/bio.c index 9b28381412d2..8381c6690dd6 100644 --- a/block/bio.c +++ b/block/bio.c @@ -665,6 +665,7 @@ 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
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