| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2024-35991: dmaengine: idxd: Convert spinlock to mutex to lock evl workqueue |
| |
| 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. |
| |
| The Linux kernel CVE team has assigned CVE-2024-35991 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.4 with commit c40bd7d9737bdcfb02d42765bc6c59b338151123 and fixed in 6.6.30 with commit 758071a35d9f3ffd84ff12169d081412a2f5f098 |
| Issue introduced in 6.4 with commit c40bd7d9737bdcfb02d42765bc6c59b338151123 and fixed in 6.8.9 with commit c9b732a9f73eadc638abdcf0a6d39bc7a0c1af5f |
| Issue introduced in 6.4 with commit c40bd7d9737bdcfb02d42765bc6c59b338151123 and fixed in 6.9 with commit d5638de827cff0fce77007e426ec0ffdedf68a44 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2024-35991 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| drivers/dma/idxd/cdev.c |
| drivers/dma/idxd/debugfs.c |
| drivers/dma/idxd/device.c |
| drivers/dma/idxd/idxd.h |
| drivers/dma/idxd/init.c |
| drivers/dma/idxd/irq.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/758071a35d9f3ffd84ff12169d081412a2f5f098 |
| https://git.kernel.org/stable/c/c9b732a9f73eadc638abdcf0a6d39bc7a0c1af5f |
| https://git.kernel.org/stable/c/d5638de827cff0fce77007e426ec0ffdedf68a44 |
