CVE-2026-74354 bpf: Take mmap_lock in zap_pages()
A race condition in the Linux kernel BPF subsystem allows attackers to cause denial of service or potentially escalate privileges via improper locking in zap_pages().
- 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-2026-74354?
CVE-2026-74354 is a high-severity vulnerability in Linux, published on 15 Aug 2026. 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:
bpf: Take mmap_lock in zap_pages()
zap_vma_range() requires the owning mm's mmap_lock to be held.
Taking mmap_read_lock under arena->lock would AB-BA against arena_vm_close() and arena_map_mmap(), both of which run with mmap_write_lock held and then acquire arena->lock. Instead drop arena->lock, mmget_not_zero() the vma's mm, take mmap_read_lock, and re-resolve the vma via find_vma() since it may have been unmapped or replaced while waiting.
Track processed vmls with a per-call generation in vml->zap_gen and serialize zap_pages() callers with a new arena->zap_mutex so concurrent callers on different uaddr ranges do not mark each other's vmls processed before the zap is done.
Which versions are affected by CVE-2026-74354?
How do I fix CVE-2026-74354?
Apply the vendor's patch.
Is CVE-2026-74354 being exploited?
There is no known exploitation of CVE-2026-74354 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-74354, DEBIAN-CVE-2026-74354, GHSA-g336-8h5f-6m63, UBUNTU-CVE-2026-74354.