| 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-2022-48887: drm/vmwgfx: Remove rcu locks from user resources |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| drm/vmwgfx: Remove rcu locks from user resources |
| |
| User resource lookups used rcu to avoid two extra atomics. Unfortunately |
| the rcu paths were buggy and it was easy to make the driver crash by |
| submitting command buffers from two different threads. Because the |
| lookups never show up in performance profiles replace them with a |
| regular spin lock which fixes the races in accesses to those shared |
| resources. |
| |
| Fixes kernel oops'es in IGT's vmwgfx execution_buffer stress test and |
| seen crashes with apps using shared resources. |
| |
| The Linux kernel CVE team has assigned CVE-2022-48887 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 4.20 with commit e14c02e6b6990e9f6ee18a214a22ac26bae1b25e and fixed in 6.1.7 with commit 7ac9578e45b20e3f3c0c8eb71f5417a499a7226a |
| Issue introduced in 4.20 with commit e14c02e6b6990e9f6ee18a214a22ac26bae1b25e and fixed in 6.2 with commit a309c7194e8a2f8bd4539b9449917913f6c2cd50 |
| |
| 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-2022-48887 |
| 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/ttm_object.c |
| drivers/gpu/drm/vmwgfx/ttm_object.h |
| drivers/gpu/drm/vmwgfx/vmwgfx_bo.c |
| drivers/gpu/drm/vmwgfx/vmwgfx_drv.h |
| drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c |
| drivers/gpu/drm/vmwgfx/vmwgfx_resource.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/7ac9578e45b20e3f3c0c8eb71f5417a499a7226a |
| https://git.kernel.org/stable/c/a309c7194e8a2f8bd4539b9449917913f6c2cd50 |
