| From bippy-7c5fe7eed585 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-2025-21911: drm/imagination: avoid deadlock on fence release |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| drm/imagination: avoid deadlock on fence release |
| |
| Do scheduler queue fence release processing on a workqueue, rather |
| than in the release function itself. |
| |
| Fixes deadlock issues such as the following: |
| |
| [ 607.400437] ============================================ |
| [ 607.405755] WARNING: possible recursive locking detected |
| [ 607.415500] -------------------------------------------- |
| [ 607.420817] weston:zfq0/24149 is trying to acquire lock: |
| [ 607.426131] ffff000017d041a0 (reservation_ww_class_mutex){+.+.}-{3:3}, at: pvr_gem_object_vunmap+0x40/0xc0 [powervr] |
| [ 607.436728] |
| but task is already holding lock: |
| [ 607.442554] ffff000017d105a0 (reservation_ww_class_mutex){+.+.}-{3:3}, at: dma_buf_ioctl+0x250/0x554 |
| [ 607.451727] |
| other info that might help us debug this: |
| [ 607.458245] Possible unsafe locking scenario: |
| |
| [ 607.464155] CPU0 |
| [ 607.466601] ---- |
| [ 607.469044] lock(reservation_ww_class_mutex); |
| [ 607.473584] lock(reservation_ww_class_mutex); |
| [ 607.478114] |
| *** DEADLOCK *** |
| |
| The Linux kernel CVE team has assigned CVE-2025-21911 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.8 with commit eaf01ee5ba28b97f96a3d3eec4c5fbfb37ee4cde and fixed in 6.12.19 with commit d993ae7360923efd6ade43a32043459a121c28c1 |
| Issue introduced in 6.8 with commit eaf01ee5ba28b97f96a3d3eec4c5fbfb37ee4cde and fixed in 6.13.7 with commit 9bd8b8d34cf4efba18766d64f817c819ed1bbde7 |
| Issue introduced in 6.8 with commit eaf01ee5ba28b97f96a3d3eec4c5fbfb37ee4cde and fixed in 6.14 with commit df1a1ed5e1bdd9cc13148e0e5549f5ebcf76cf13 |
| |
| 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-2025-21911 |
| 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/gpu/drm/imagination/pvr_queue.c |
| drivers/gpu/drm/imagination/pvr_queue.h |
| |
| |
| 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/d993ae7360923efd6ade43a32043459a121c28c1 |
| https://git.kernel.org/stable/c/9bd8b8d34cf4efba18766d64f817c819ed1bbde7 |
| https://git.kernel.org/stable/c/df1a1ed5e1bdd9cc13148e0e5549f5ebcf76cf13 |
