CVE-2022-50552 blk-mq: use quiesced elevator switch when reinitializing queues
A race condition in the Linux kernel block layer can cause a use-after-free error, leading to kernel panics and denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-50552?
CVE-2022-50552 is a high-severity use after free vulnerability in Linux kernel, published on 7 Oct 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
blk-mq: use quiesced elevator switch when reinitializing queues
The hctx's run_work may be racing with the elevator switch when reinitializing hardware queues. The queue is merely frozen in this context, but that only prevents requests from allocating and doesn't stop the hctx work from running. The work may get an elevator pointer that's being torn down, and can result in use-after-free errors and kernel panics (example below). Use the quiesced elevator switch instead, and make the previous one static since it is now only used locally.
nvme nvme0: resetting controller nvme nvme0: 32/0/0 default/read/poll queues BUG: kernel NULL pointer dereference, address: 0000000000000008 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 80000020c8861067 P4D 80000020c8861067 PUD 250f8c8067 PMD 0 Oops: 0000 [#1] SMP PTI Workqueue: kblockd blk_mq_run_work_fn RIP: 0010:kyber_has_work+0x29/0x70
...
Call Trace: __blk_mq_do_dispatch_sched+0x83/0x2b0 __blk_mq_sched_dispatch_requests+0x12e/0x170 blk_mq_sched_dispatch_requests+0x30/0x60 __blk_mq_run_hw_queue+0x2b/0x50 process_one_work+0x1ef/0x380 worker_thread+0x2d/0x3e0
Weakness: CWE-416
Which versions are affected by CVE-2022-50552?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-50552?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2022-50552 being exploited?
There is no known exploitation of CVE-2022-50552 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-76631, DEBIAN-CVE-2022-50552, GHSA-8p56-6q52-jgv2, ROOT-OS-DEBIAN-11-CVE-2022-50552, ROOT-OS-UBUNTU-2204-CVE-2022-50552, UBUNTU-CVE-2022-50552.