| From bippy-1.2.0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@kernel.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2024-43863: drm/vmwgfx: Fix a deadlock in dma buf fence polling |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| drm/vmwgfx: Fix a deadlock in dma buf fence polling |
| |
| Introduce a version of the fence ops that on release doesn't remove |
| the fence from the pending list, and thus doesn't require a lock to |
| fix poll->fence wait->fence unref deadlocks. |
| |
| vmwgfx overwrites the wait callback to iterate over the list of all |
| fences and update their status, to do that it holds a lock to prevent |
| the list modifcations from other threads. The fence destroy callback |
| both deletes the fence and removes it from the list of pending |
| fences, for which it holds a lock. |
| |
| dma buf polling cb unrefs a fence after it's been signaled: so the poll |
| calls the wait, which signals the fences, which are being destroyed. |
| The destruction tries to acquire the lock on the pending fences list |
| which it can never get because it's held by the wait from which it |
| was called. |
| |
| Old bug, but not a lot of userspace apps were using dma-buf polling |
| interfaces. Fix those, in particular this fixes KDE stalls/deadlock. |
| |
| The Linux kernel CVE team has assigned CVE-2024-43863 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 3.18 with commit 2298e804e96eb3635c39519c8287befd92460303 and fixed in 5.10.238 with commit 9908dc0d2ef0e4aec8a242c098455729c0e2f017 |
| Issue introduced in 3.18 with commit 2298e804e96eb3635c39519c8287befd92460303 and fixed in 5.15.165 with commit 9e20d028d8d1deb1e7fed18f22ffc01669cf3237 |
| Issue introduced in 3.18 with commit 2298e804e96eb3635c39519c8287befd92460303 and fixed in 6.1.104 with commit 3b933b16c996af8adb6bc1b5748a63dfb41a82bc |
| Issue introduced in 3.18 with commit 2298e804e96eb3635c39519c8287befd92460303 and fixed in 6.6.45 with commit a8943969f9ead2fd3044fc826140a21622ef830e |
| Issue introduced in 3.18 with commit 2298e804e96eb3635c39519c8287befd92460303 and fixed in 6.10.4 with commit c98ab18b9f315ff977c2c65d7c71298ef98be8e3 |
| Issue introduced in 3.18 with commit 2298e804e96eb3635c39519c8287befd92460303 and fixed in 6.11 with commit e58337100721f3cc0c7424a18730e4f39844934f |
| |
| 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-2024-43863 |
| 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/vmwgfx/vmwgfx_fence.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/9908dc0d2ef0e4aec8a242c098455729c0e2f017 |
| https://git.kernel.org/stable/c/9e20d028d8d1deb1e7fed18f22ffc01669cf3237 |
| https://git.kernel.org/stable/c/3b933b16c996af8adb6bc1b5748a63dfb41a82bc |
| https://git.kernel.org/stable/c/a8943969f9ead2fd3044fc826140a21622ef830e |
| https://git.kernel.org/stable/c/c98ab18b9f315ff977c2c65d7c71298ef98be8e3 |
| https://git.kernel.org/stable/c/e58337100721f3cc0c7424a18730e4f39844934f |
