CVE-2026-90046

Description

In the Linux kernel, the following vulnerability has been resolved: mm/page_alloc: don't spin_trylock() in NMI on UP Patch series "mm/page_alloc: fixes for free_pages_nolock() on RT/UP". Pre-existing bugs found by Sashiko during review of this other series: https://lore.kernel.org/all/20260703-alloc-trylock-v5-0-c87b714e19d3@google.com/ I have not reproduced these bugs, and I suspect there is no real-world user that is affected by them. This patch (of 2): As noted in can_spin_trylock(), using this is unsafe in this context. commit 620b46ed6ae17 ("mm/page_alloc: return NULL early from alloc_frozen_pages_nolock() in NMI on UP") fixed this on the alloc side but missed the free side. Impact: If BPF programs using these features in NMI (probably tracing) are present on non-SMP builds this might crash the kernel and is probably exploitable by local attackers for privilege escalation.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

References

• https://git.kernel.org/stable/c/06c76d3c389ff504052f64b1acee44651bd847fa ↗
• https://git.kernel.org/stable/c/68a069b407303e71db371df85036101e8ff59280 ↗
• https://git.kernel.org/stable/c/3105ae628fb785d48b49256468be4f21a7b3cfc0 ↗