CVE-2023-52903 io_uring: lock overflowing for IOPOLL
A race condition in the Linux kernel's io_uring IOPOLL implementation can cause a kernel warning and potential 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-2023-52903?
CVE-2023-52903 is a high-severity vulnerability in Linux kernel, published on 21 Aug 2024. 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:
io_uring: lock overflowing for IOPOLL
syzbot reports an issue with overflow filling for IOPOLL:
WARNING: CPU: 0 PID: 28 at io_uring/io_uring.c:734 io_cqring_event_overflow+0x1c0/0x230 io_uring/io_uring.c:734 CPU: 0 PID: 28 Comm: kworker/u4:1 Not tainted 6.2.0-rc3-syzkaller-16369-g358a161a6a9e #0 Workqueue: events_unbound io_ring_exit_work Call trace: io_cqring_event_overflow+0x1c0/0x230 io_uring/io_uring.c:734 io_req_cqe_overflow+0x5c/0x70 io_uring/io_uring.c:773 io_fill_cqe_req io_uring/io_uring.h:168 [inline] io_do_iopoll+0x474/0x62c io_uring/rw.c:1065 io_iopoll_try_reap_events+0x6c/0x108 io_uring/io_uring.c:1513 io_uring_try_cancel_requests+0x13c/0x258 io_uring/io_uring.c:3056 io_ring_exit_work+0xec/0x390 io_uring/io_uring.c:2869 process_one_work+0x2d8/0x504 kernel/workqueue.c:2289 worker_thread+0x340/0x610 kernel/workqueue.c:2436 kthread+0x12c/0x158 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:863
There is no real problem for normal IOPOLL as flush is also called with uring_lock taken, but it's getting more complicated for IOPOLL|SQPOLL, for which __io_cqring_overflow_flush() happens from the CQ waiting path.
Weakness: CWE-667
Which versions are affected by CVE-2023-52903?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2023-52903?
Apply the vendor's patch.
Is CVE-2023-52903 being exploited?
There is no known exploitation of CVE-2023-52903 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2023-52903, DEBIAN-CVE-2023-52903, GHSA-2wjg-qcgr-7p52, UBUNTU-CVE-2023-52903.