| 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-2024-35887: ax25: fix use-after-free bugs caused by ax25_ds_del_timer |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| ax25: fix use-after-free bugs caused by ax25_ds_del_timer |
| |
| When the ax25 device is detaching, the ax25_dev_device_down() |
| calls ax25_ds_del_timer() to cleanup the slave_timer. When |
| the timer handler is running, the ax25_ds_del_timer() that |
| calls del_timer() in it will return directly. As a result, |
| the use-after-free bugs could happen, one of the scenarios |
| is shown below: |
| |
| (Thread 1) | (Thread 2) |
| | ax25_ds_timeout() |
| ax25_dev_device_down() | |
| ax25_ds_del_timer() | |
| del_timer() | |
| ax25_dev_put() //FREE | |
| | ax25_dev-> //USE |
| |
| In order to mitigate bugs, when the device is detaching, use |
| timer_shutdown_sync() to stop the timer. |
| |
| The Linux kernel CVE team has assigned CVE-2024-35887 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 2.6.12 with commit 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and fixed in 6.6.26 with commit 74204bf9050f7627aead9875fe4e07ba125cb19b |
| Issue introduced in 2.6.12 with commit 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and fixed in 6.8.5 with commit c6a368f9c7af4c14b14d390c2543af8001c9bdb9 |
| Issue introduced in 2.6.12 with commit 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and fixed in 6.9 with commit fd819ad3ecf6f3c232a06b27423ce9ed8c20da89 |
| |
| 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-2024-35887 |
| 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: |
| net/ax25/ax25_dev.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/74204bf9050f7627aead9875fe4e07ba125cb19b |
| https://git.kernel.org/stable/c/c6a368f9c7af4c14b14d390c2543af8001c9bdb9 |
| https://git.kernel.org/stable/c/fd819ad3ecf6f3c232a06b27423ce9ed8c20da89 |
