Description (CNA)
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.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 4ac4546821584736798aaa9e97da9f6eaf689ea3 before 239cec25a22662dbd80f57d94b38178c8be95269; affected 4ac4546821584736798aaa9e97da9f6eaf689ea3 before d0862de7c866c5bd7c32531f66738c21197af888; affected 4ac4546821584736798aaa9e97da9f6eaf689ea3 before 43683bb280330f3d36f0f2a3932a4867b9603e9c; affected 4ac4546821584736798aaa9e97da9f6eaf689ea3 before d8e27d2d22b6e2df3a0125b8c08e9aace38c954c |
| Linux / Linux | affected 6.7; unaffected 0 before 6.7; unaffected 6.12.91 through 6.12.*; unaffected 6.18.33 through 6.18.*; unaffected 7.0.10 through 7.0.*; unaffected 7.1 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/239cec25a22662dbd80f57d94b38178c8be95269
- https://git.kernel.org/stable/c/d0862de7c866c5bd7c32531f66738c21197af888
- https://git.kernel.org/stable/c/43683bb280330f3d36f0f2a3932a4867b9603e9c
- https://git.kernel.org/stable/c/d8e27d2d22b6e2df3a0125b8c08e9aace38c954c
ADP enrichment
A flaw was found in the Linux kernel's Berkeley Packet Filter (BPF) subsystem. This use-after-free vulnerability occurs when the `task_vma` iterator reads task memory without properly acquiring a reference, allowing the memory structure to be freed concurrently while still in use. This can lead to system instability or a denial of service (DoS). Additionally, improper handling of interrupt-disabled contexts could result in a deadlock.
No English description supplied.
No references supplied.