| 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-2021-47324: watchdog: Fix possible use-after-free in wdt_startup() |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| watchdog: Fix possible use-after-free in wdt_startup() |
| |
| 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-2021-47324 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 4.4.276 with commit 63a3dc24bd053792f84cb4eef0168b1266202a02 |
| Fixed in 4.9.276 with commit 862f2b5a7c38762ac9e369daefbf361a91aca685 |
| Fixed in 4.14.240 with commit 0ac50a76cf3cd63db000648b3b19f3f98b8aaa76 |
| Fixed in 4.19.198 with commit dc9403097be52d57a5c9c35efa9be79d166a78af |
| Fixed in 5.4.134 with commit 146cc288fb80c662c9c35e7bc58325d1ac0a7875 |
| Fixed in 5.10.52 with commit a397cb4576fc2fc802562418b3a50b8f67d60d31 |
| Fixed in 5.12.19 with commit b4ebf4a4692e84163a69444c70ad515de06e2259 |
| Fixed in 5.13.4 with commit 8adbbe6c86bb13e14f8a19e036ae5f4f5661fd90 |
| Fixed in 5.14 with commit c08a6b31e4917034f0ed0cb457c3bb209576f542 |
| |
| 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-2021-47324 |
| 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/sbc60xxwdt.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/63a3dc24bd053792f84cb4eef0168b1266202a02 |
| https://git.kernel.org/stable/c/862f2b5a7c38762ac9e369daefbf361a91aca685 |
| https://git.kernel.org/stable/c/0ac50a76cf3cd63db000648b3b19f3f98b8aaa76 |
| https://git.kernel.org/stable/c/dc9403097be52d57a5c9c35efa9be79d166a78af |
| https://git.kernel.org/stable/c/146cc288fb80c662c9c35e7bc58325d1ac0a7875 |
| https://git.kernel.org/stable/c/a397cb4576fc2fc802562418b3a50b8f67d60d31 |
| https://git.kernel.org/stable/c/b4ebf4a4692e84163a69444c70ad515de06e2259 |
| https://git.kernel.org/stable/c/8adbbe6c86bb13e14f8a19e036ae5f4f5661fd90 |
| https://git.kernel.org/stable/c/c08a6b31e4917034f0ed0cb457c3bb209576f542 |
