High · published October 1, 2025
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.
| Product | Versions | Fixed in |
|---|---|---|
| linux/linux_kernel | ≥ 3.8.1, < 4.14.316 | 4.14.316 |
| linux/linux_kernel | ≥ 4.15, < 4.19.284 | 4.19.284 |
| linux/linux_kernel | ≥ 4.20, < 5.4.244 | 5.4.244 |
| linux/linux_kernel | ≥ 5.5, < 5.10.181 | 5.10.181 |
| linux/linux_kernel | ≥ 5.11, < 5.15.113 | 5.15.113 |
| linux/linux_kernel | ≥ 5.16, < 6.1.30 | 6.1.30 |
| linux/linux_kernel | ≥ 6.2, < 6.3.4 | 6.3.4 |
| linux/linux_kernel | all versions | — |
| linux/linux_kernel | all versions | — |
| linux/linux_kernel | all versions | — |
| linux/linux_kernel | all versions | — |
| linux/linux_kernel | all versions | — |