CVE-2023-53111 loop: Fix use-after-free issues
A use-after-free vulnerability in the Linux kernel loop driver allows attackers to cause a system crash via kernel NULL pointer dereference.
- 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-2023-53111?
CVE-2023-53111 is a high-severity use after free vulnerability in Linux kernel, published on 2 May 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:
loop: Fix use-after-free issues
do_req_filebacked() calls blk_mq_complete_request() synchronously or asynchronously when using asynchronous I/O unless memory allocation fails. Hence, modify loop_handle_cmd() such that it does not dereference 'cmd' nor 'rq' after do_req_filebacked() finished unless we are sure that the request has not yet been completed. This patch fixes the following kernel crash:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000054 Call trace: css_put.42938+0x1c/0x1ac loop_process_work+0xc8c/0xfd4 loop_rootcg_workfn+0x24/0x34 process_one_work+0x244/0x558 worker_thread+0x400/0x8fc kthread+0x16c/0x1e0 ret_from_fork+0x10/0x20
Weakness: CWE-416
Which versions are affected by CVE-2023-53111?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2023-53111?
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-2023-53111 being exploited?
There is no known exploitation of CVE-2023-53111 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2023-53111, DEBIAN-CVE-2023-53111, GHSA-8xqr-m9jg-qc5f, ROOT-OS-DEBIAN-11-CVE-2023-53111, UBUNTU-CVE-2023-53111.