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authorYu Kuai <yukuai3@huawei.com>2023-01-30 09:41:36 +0800
committerJens Axboe <axboe@kernel.dk>2023-01-29 18:57:01 -0700
commitb600de2d7d3a16f9007fad1bdae82a3951a26af2 (patch)
tree4a676a3d482d0f4e89c2468d341b28895d62d26e /block/bfq-iosched.c
parentdb3ba974c2bc895ba39689a364cb7a49c0fe779f (diff)
block, bfq: fix uaf for bfqq in bic_set_bfqq()
After commit 64dc8c732f5c ("block, bfq: fix possible uaf for 'bfqq->bic'"), bic->bfqq will be accessed in bic_set_bfqq(), however, in some context bic->bfqq will be freed, and bic_set_bfqq() is called with the freed bic->bfqq. Fix the problem by always freeing bfqq after bic_set_bfqq(). Fixes: 64dc8c732f5c ("block, bfq: fix possible uaf for 'bfqq->bic'") Reported-and-tested-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com> Signed-off-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20230130014136.591038-1-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/bfq-iosched.c')
-rw-r--r--block/bfq-iosched.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index ccf2204477a5..380e9bda2e57 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -5425,9 +5425,11 @@ static void bfq_check_ioprio_change(struct bfq_io_cq *bic, struct bio *bio)
bfqq = bic_to_bfqq(bic, false);
if (bfqq) {
- bfq_release_process_ref(bfqd, bfqq);
+ struct bfq_queue *old_bfqq = bfqq;
+
bfqq = bfq_get_queue(bfqd, bio, false, bic, true);
bic_set_bfqq(bic, bfqq, false);
+ bfq_release_process_ref(bfqd, old_bfqq);
}
bfqq = bic_to_bfqq(bic, true);