| 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-2021-47339: media: v4l2-core: explicitly clear ioctl input data |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| media: v4l2-core: explicitly clear ioctl input data |
| |
| As seen from a recent syzbot bug report, mistakes in the compat ioctl |
| implementation can lead to uninitialized kernel stack data getting used |
| as input for driver ioctl handlers. |
| |
| The reported bug is now fixed, but it's possible that other related |
| bugs are still present or get added in the future. As the drivers need |
| to check user input already, the possible impact is fairly low, but it |
| might still cause an information leak. |
| |
| To be on the safe side, always clear the entire ioctl buffer before |
| calling the conversion handler functions that are meant to initialize |
| them. |
| |
| The Linux kernel CVE team has assigned CVE-2021-47339 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 5.12.18 with commit dc02c0b2bd6096f2f3ce63e1fc317aeda05f74d8 |
| Fixed in 5.13.3 with commit bfb48b54db25c3b4ef4bef5e0691464ebc4aa335 |
| Fixed in 5.14 with commit 7b53cca764f9b291b7907fcd39d9e66ad728ee0b |
| |
| 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-2021-47339 |
| 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/media/v4l2-core/v4l2-ioctl.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/dc02c0b2bd6096f2f3ce63e1fc317aeda05f74d8 |
| https://git.kernel.org/stable/c/bfb48b54db25c3b4ef4bef5e0691464ebc4aa335 |
| https://git.kernel.org/stable/c/7b53cca764f9b291b7907fcd39d9e66ad728ee0b |
