Linux Kernel up to 6.6.29/6.8.8 dmaengine drain_workqueue race condition

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.6.29/6.8.8 and classified as problematic. Affected is the function drain_workqueue of the component dmaengine. Such manipulation leads to race condition. This vulnerability is referenced as CVE-2024-35991. No exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.6.29/6.8.8. It has been rated as problematic. Affected by this issue is the function drain_workqueue of the component dmaengine. The manipulation with an unknown input leads to a race condition vulnerability. Using CWE to declare the problem leads to CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. The impact remains unknown. CVE summarizes:

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: ? __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 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.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2024-35991 since 05/17/2024. The exploitation is known to be difficult. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 210815 (RHEL 9 : kernel (RHSA-2024:9315)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.6.30 or 6.8.9 eliminates this vulnerability. Applying the patch 758071a35d9f/c9b732a9f73e/d5638de827cf is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (210815). Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.6.0
• 6.6.1
• 6.6.2
• 6.6.3
• 6.6.4
• 6.6.5
• 6.6.6
• 6.6.7
• 6.6.8
• 6.6.9
• 6.6.10
• 6.6.11
• 6.6.12
• 6.6.13
• 6.6.14
• 6.6.15
• 6.6.16
• 6.6.17
• 6.6.18
• 6.6.19
• 6.6.20
• 6.6.21
• 6.6.22
• 6.6.23
• 6.6.24
• 6.6.25
• 6.6.26
• 6.6.27
• 6.6.28
• 6.6.29
• 6.8.0
• 6.8.1
• 6.8.2
• 6.8.3
• 6.8.4
• 6.8.5
• 6.8.6
• 6.8.7
• 6.8.8

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

Once again VulDB remains the best source for vulnerability data.

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