| 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-2021-47356: mISDN: fix possible use-after-free in HFC_cleanup() |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| mISDN: fix possible use-after-free in HFC_cleanup() |
| |
| 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-2021-47356 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 4.4.276 with commit 49331c07ef0f8fdfa42b30ba6a83a657b29d7fbe |
| Fixed in 4.9.276 with commit 54ff3202928952a100c477248e65ac6db01258a7 |
| Fixed in 4.14.240 with commit 7867ddc5f3de7f289aee63233afc0df4b62834c5 |
| Fixed in 4.19.198 with commit 5f2818185da0fe82a932f0856633038b66faf124 |
| Fixed in 5.4.133 with commit 3ecd228c636ee17c14662729737fa07242a93cb0 |
| Fixed in 5.10.51 with commit b7ee9ae1e0cf55a037c4a99af2acc5d78cb7802d |
| Fixed in 5.12.18 with commit 61370ff07e0acc657559a8fac02551dfeb9d3020 |
| Fixed in 5.13.3 with commit ed7c3739d0a07e2ec3ccbffe7e93cea01c438cda |
| Fixed in 5.14 with commit 009fc857c5f6fda81f2f7dd851b2d54193a8e733 |
| |
| 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-2021-47356 |
| 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/isdn/hardware/mISDN/hfcpci.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/49331c07ef0f8fdfa42b30ba6a83a657b29d7fbe |
| https://git.kernel.org/stable/c/54ff3202928952a100c477248e65ac6db01258a7 |
| https://git.kernel.org/stable/c/7867ddc5f3de7f289aee63233afc0df4b62834c5 |
| https://git.kernel.org/stable/c/5f2818185da0fe82a932f0856633038b66faf124 |
| https://git.kernel.org/stable/c/3ecd228c636ee17c14662729737fa07242a93cb0 |
| https://git.kernel.org/stable/c/b7ee9ae1e0cf55a037c4a99af2acc5d78cb7802d |
| https://git.kernel.org/stable/c/61370ff07e0acc657559a8fac02551dfeb9d3020 |
| https://git.kernel.org/stable/c/ed7c3739d0a07e2ec3ccbffe7e93cea01c438cda |
| https://git.kernel.org/stable/c/009fc857c5f6fda81f2f7dd851b2d54193a8e733 |
