| 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-2021-47534: drm/vc4: kms: Add missing drm_crtc_commit_put |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| drm/vc4: kms: Add missing drm_crtc_commit_put |
| |
| Commit 9ec03d7f1ed3 ("drm/vc4: kms: Wait on previous FIFO users before a |
| commit") introduced a global state for the HVS, with each FIFO storing |
| the current CRTC commit so that we can properly synchronize commits. |
| |
| However, the refcounting was off and we thus ended up leaking the |
| drm_crtc_commit structure every commit. Add a drm_crtc_commit_put to |
| prevent the leakage. |
| |
| The Linux kernel CVE team has assigned CVE-2021-47534 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.12 with commit 9ec03d7f1ed394897891319a4dda75f52c5d292d and fixed in 5.15.7 with commit 53f9601e908d42481addd67cdb01a9288c611124 |
| Issue introduced in 5.12 with commit 9ec03d7f1ed394897891319a4dda75f52c5d292d and fixed in 5.16 with commit 049cfff8d53a30cae3349ff71a4c01b7d9981bc2 |
| |
| 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-2021-47534 |
| 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/vc4/vc4_kms.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/53f9601e908d42481addd67cdb01a9288c611124 |
| https://git.kernel.org/stable/c/049cfff8d53a30cae3349ff71a4c01b7d9981bc2 |
