diff options
| author | Ming Lei <ming.lei@redhat.com> | 2026-01-21 17:38:54 +0800 |
|---|---|---|
| committer | Keith Busch <kbusch@kernel.org> | 2026-01-21 07:21:19 -0800 |
| commit | 0fcee2cfc4b2e16e62ff8e0cc2cd8dd24efad65e (patch) | |
| tree | 28b12e6dd8f874b33d9ad8cc1de55607e6873352 | |
| parent | e7e1cc18f120a415646be12470169a978a1adcd9 (diff) | |
nvmet: fix race in nvmet_bio_done() leading to NULL pointer dereference
There is a race condition in nvmet_bio_done() that can cause a NULL
pointer dereference in blk_cgroup_bio_start():
1. nvmet_bio_done() is called when a bio completes
2. nvmet_req_complete() is called, which invokes req->ops->queue_response(req)
3. The queue_response callback can re-queue and re-submit the same request
4. The re-submission reuses the same inline_bio from nvmet_req
5. Meanwhile, nvmet_req_bio_put() (called after nvmet_req_complete)
invokes bio_uninit() for inline_bio, which sets bio->bi_blkg to NULL
6. The re-submitted bio enters submit_bio_noacct_nocheck()
7. blk_cgroup_bio_start() dereferences bio->bi_blkg, causing a crash:
BUG: kernel NULL pointer dereference, address: 0000000000000028
#PF: supervisor read access in kernel mode
RIP: 0010:blk_cgroup_bio_start+0x10/0xd0
Call Trace:
submit_bio_noacct_nocheck+0x44/0x250
nvmet_bdev_execute_rw+0x254/0x370 [nvmet]
process_one_work+0x193/0x3c0
worker_thread+0x281/0x3a0
Fix this by reordering nvmet_bio_done() to call nvmet_req_bio_put()
BEFORE nvmet_req_complete(). This ensures the bio is cleaned up before
the request can be re-submitted, preventing the race condition.
Fixes: 190f4c2c863a ("nvmet: fix memory leak of bio integrity")
Cc: Dmitry Bogdanov <d.bogdanov@yadro.com>
Cc: stable@vger.kernel.org
Cc: Guangwu Zhang <guazhang@redhat.com>
Link: http://www.mail-archive.com/debian-kernel@lists.debian.org/msg146238.html
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
| -rw-r--r-- | drivers/nvme/target/io-cmd-bdev.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/nvme/target/io-cmd-bdev.c b/drivers/nvme/target/io-cmd-bdev.c index 8d246b8ca604..0103815542d4 100644 --- a/drivers/nvme/target/io-cmd-bdev.c +++ b/drivers/nvme/target/io-cmd-bdev.c @@ -180,9 +180,10 @@ u16 blk_to_nvme_status(struct nvmet_req *req, blk_status_t blk_sts) static void nvmet_bio_done(struct bio *bio) { struct nvmet_req *req = bio->bi_private; + blk_status_t blk_status = bio->bi_status; - nvmet_req_complete(req, blk_to_nvme_status(req, bio->bi_status)); nvmet_req_bio_put(req, bio); + nvmet_req_complete(req, blk_to_nvme_status(req, blk_status)); } #ifdef CONFIG_BLK_DEV_INTEGRITY |