Linux Kernel BPF Task VMA Iterator Use-After-Free
CVE-2026-53085 Published on June 24, 2026
bpf: fix mm lifecycle in open-coded task_vma iterator
In the Linux kernel, the following vulnerability has been resolved:
bpf: fix mm lifecycle in open-coded task_vma iterator
The open-coded task_vma iterator reads task->mm locklessly and acquires
mmap_read_trylock() but never calls mmget(). If the task exits
concurrently, the mm_struct can be freed as it is not
SLAB_TYPESAFE_BY_RCU, resulting in a use-after-free.
Safely read task->mm with a trylock on alloc_lock and acquire an mm
reference. Drop the reference via bpf_iter_mmput_async() in _destroy()
and error paths. bpf_iter_mmput_async() is a local wrapper around
mmput_async() with a fallback to mmput() on !CONFIG_MMU.
Reject irqs-disabled contexts (including NMI) up front. Operations used
by _next() and _destroy() (mmap_read_unlock, bpf_iter_mmput_async)
take spinlocks with IRQs disabled (pool->lock, pi_lock). Running from
NMI or from a tracepoint that fires with those locks held could
deadlock.
A trylock on alloc_lock is used instead of the blocking task_lock()
(get_task_mm) to avoid a deadlock when a softirq BPF program iterates
a task that already holds its alloc_lock on the same CPU.
Products Associated with CVE-2026-53085
Want to know whenever a new CVE is published for Linux Kernel? stack.watch will email you.
Affected Versions
Linux:- Version 4ac4546821584736798aaa9e97da9f6eaf689ea3 and below 239cec25a22662dbd80f57d94b38178c8be95269 is affected.
- Version 4ac4546821584736798aaa9e97da9f6eaf689ea3 and below d0862de7c866c5bd7c32531f66738c21197af888 is affected.
- Version 4ac4546821584736798aaa9e97da9f6eaf689ea3 and below 43683bb280330f3d36f0f2a3932a4867b9603e9c is affected.
- Version 4ac4546821584736798aaa9e97da9f6eaf689ea3 and below d8e27d2d22b6e2df3a0125b8c08e9aace38c954c is affected.
- Version 6.7 is affected.
- Before 6.7 is unaffected.
- Version 6.12.91, <= 6.12.* is unaffected.
- Version 6.18.33, <= 6.18.* is unaffected.
- Version 7.0.10, <= 7.0.* is unaffected.
- Version 7.1, <= * is unaffected.