| 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-2021-47323: watchdog: sc520_wdt: Fix possible use-after-free in wdt_turnoff() |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| watchdog: sc520_wdt: Fix possible use-after-free in wdt_turnoff() |
| |
| This module's remove path calls del_timer(). However, that function |
| does not wait until the timer handler finishes. This means that the |
| timer handler may still be running after the driver's remove function |
| has finished, which would result in a use-after-free. |
| |
| Fix by calling del_timer_sync(), which makes sure the timer handler |
| has finished, and unable to re-schedule itself. |
| |
| The Linux kernel CVE team has assigned CVE-2021-47323 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 4.4.276 with commit 0015581a79bbf8e521f85dddb7d3e4a66b9f51d4 |
| Fixed in 4.9.276 with commit b4565a8a2d6bffb05bfbec11399d261ec16fe373 |
| Fixed in 4.14.240 with commit 2aef07017fae21c3d8acea9656b10e3b9c0f1e04 |
| Fixed in 4.19.198 with commit 522e75ed63f67e815d4ec0deace67df22d9ce78e |
| Fixed in 5.4.134 with commit 7c56c5508dc20a6b133bc669fc34327a6711c24c |
| Fixed in 5.10.52 with commit a173e3b62cf6dd3c4a0a10c8a82eedfcae81a566 |
| Fixed in 5.12.19 with commit b3c41ea5bc34d8c7b19e230d80e0e555c6f5057d |
| Fixed in 5.13.4 with commit f0feab82f6a0323f54d85e8b512a2be64f83648a |
| Fixed in 5.14 with commit 90b7c141132244e8e49a34a4c1e445cce33e07f4 |
| |
| 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-2021-47323 |
| 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/watchdog/sc520_wdt.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/0015581a79bbf8e521f85dddb7d3e4a66b9f51d4 |
| https://git.kernel.org/stable/c/b4565a8a2d6bffb05bfbec11399d261ec16fe373 |
| https://git.kernel.org/stable/c/2aef07017fae21c3d8acea9656b10e3b9c0f1e04 |
| https://git.kernel.org/stable/c/522e75ed63f67e815d4ec0deace67df22d9ce78e |
| https://git.kernel.org/stable/c/7c56c5508dc20a6b133bc669fc34327a6711c24c |
| https://git.kernel.org/stable/c/a173e3b62cf6dd3c4a0a10c8a82eedfcae81a566 |
| https://git.kernel.org/stable/c/b3c41ea5bc34d8c7b19e230d80e0e555c6f5057d |
| https://git.kernel.org/stable/c/f0feab82f6a0323f54d85e8b512a2be64f83648a |
| https://git.kernel.org/stable/c/90b7c141132244e8e49a34a4c1e445cce33e07f4 |
