CVE-2023-53484 lib: cpu_rmap: Avoid use after free on rmap->obj array entries
A use-after-free vulnerability in the Linux kernel's cpu_rmap library could allow attackers to execute arbitrary code or escalate privileges.
- 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-2023-53484?
CVE-2023-53484 is a high-severity use after free vulnerability in Linux kernel, published on 1 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:
lib: cpu_rmap: Avoid use after free on rmap->obj array entries
When calling irq_set_affinity_notifier() with NULL at the notify argument, it will cause freeing of the glue pointer in the corresponding array entry but will leave the pointer in the array. A subsequent call to free_irq_cpu_rmap() will try to free this entry again leading to possible use after free.
Fix that by setting NULL to the array entry and checking that we have non-zero at the array entry when iterating over the array in free_irq_cpu_rmap().
The current code does not suffer from this since there are no cases where irq_set_affinity_notifier(irq, NULL) (note the NULL passed for the notify arg) is called, followed by a call to free_irq_cpu_rmap() so we don't hit and issue. Subsequent patches in this series excersize this flow, hence the required fix.
Weakness: CWE-416
Which versions are affected by CVE-2023-53484?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2023-53484?
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-2023-53484 being exploited?
There is no known exploitation of CVE-2023-53484 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2023-53484, DEBIAN-CVE-2023-53484, GHSA-9598-2w9x-r9v4, UBUNTU-CVE-2023-53484.