CVE-2024-35991 dmaengine: idxd: Convert spinlock to mutex to lock evl workqueue
A race condition in the Intel DSA driver causes a kernel warning and potential instability when draining workqueues, requiring a patch to switch locking mechanisms.
- 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-2024-35991?
CVE-2024-35991 is a medium-severity vulnerability in Linux kernel, published on 20 May 2024. 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:
dmaengine: idxd: Convert spinlock to mutex to lock evl workqueue
drain_workqueue() cannot be called safely in a spinlocked context due to possible task rescheduling. In the multi-task scenario, calling queue_work() while drain_workqueue() will lead to a Call Trace as pushing a work on a draining workqueue is not permitted in spinlocked context. Call Trace: <TASK> ? __warn+0x7d/0x140 ? __queue_work+0x2b2/0x440 ? report_bug+0x1f8/0x200 ? handle_bug+0x3c/0x70 ? exc_invalid_op+0x18/0x70 ? asm_exc_invalid_op+0x1a/0x20 ? __queue_work+0x2b2/0x440 queue_work_on+0x28/0x30 idxd_misc_thread+0x303/0x5a0 [idxd] ? __schedule+0x369/0xb40 ? __pfx_irq_thread_fn+0x10/0x10 ? irq_thread+0xbc/0x1b0 irq_thread_fn+0x21/0x70 irq_thread+0x102/0x1b0 ? preempt_count_add+0x74/0xa0 ? __pfx_irq_thread_dtor+0x10/0x10 ? __pfx_irq_thread+0x10/0x10 kthread+0x103/0x140 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x31/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1b/0x30 </TASK>
The current implementation uses a spinlock to protect event log workqueue and will lead to the Call Trace due to potential task rescheduling.
To address the locking issue, convert the spinlock to mutex, allowing the drain_workqueue() to be called in a safe mutex-locked context.
This change ensures proper synchronization when accessing the event log workqueue, preventing potential Call Trace and improving the overall robustness of the code.
Weakness: CWE-667
Which versions are affected by CVE-2024-35991?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-35991?
Apply the vendor's patch.
Is CVE-2024-35991 being exploited?
There is no known exploitation of CVE-2024-35991 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2024-35991, DEBIAN-CVE-2024-35991, GHSA-g55p-876w-v4vx, UBUNTU-CVE-2024-35991.