CVE-2023-53484: Linux Kernel

High severity, CVSS 7.8. EPSS: 0.2% chance of exploitation in the next 30 days.

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.

Affected products

• Linux Linux Kernel: from 3.8.1, before 4.14.316 (fixed in 4.14.316); from 4.15, before 4.19.284 (fixed in 4.19.284); from 4.20, before 5.4.244 (fixed in 5.4.244); from 5.5, before 5.10.181 (fixed in 5.10.181); from 5.11, before 5.15.113 (fixed in 5.15.113); from 5.16, before 6.1.30 (fixed in 6.1.30); …

Published 2025-10-01. Last modified 2026-08-04.