| 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-2024-46845: tracing/timerlat: Only clear timer if a kthread exists |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| tracing/timerlat: Only clear timer if a kthread exists |
| |
| The timerlat tracer can use user space threads to check for osnoise and |
| timer latency. If the program using this is killed via a SIGTERM, the |
| threads are shutdown one at a time and another tracing instance can start |
| up resetting the threads before they are fully closed. That causes the |
| hrtimer assigned to the kthread to be shutdown and freed twice when the |
| dying thread finally closes the file descriptors, causing a use-after-free |
| bug. |
| |
| Only cancel the hrtimer if the associated thread is still around. Also add |
| the interface_lock around the resetting of the tlat_var->kthread. |
| |
| Note, this is just a quick fix that can be backported to stable. A real |
| fix is to have a better synchronization between the shutdown of old |
| threads and the starting of new ones. |
| |
| The Linux kernel CVE team has assigned CVE-2024-46845 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.5 with commit e88ed227f639ebcb31ed4e5b88756b47d904584b and fixed in 6.6.51 with commit 8c72f0b2c45f21cb8b00fc37f79f632d7e46c2ed |
| Issue introduced in 6.5 with commit e88ed227f639ebcb31ed4e5b88756b47d904584b and fixed in 6.10.10 with commit 8a9d0d405159e9c796ddf771f7cff691c1a2bc1e |
| Issue introduced in 6.5 with commit e88ed227f639ebcb31ed4e5b88756b47d904584b and fixed in 6.11 with commit e6a53481da292d970d1edf0d8831121d1c5e2f0d |
| |
| 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-2024-46845 |
| 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: |
| kernel/trace/trace_osnoise.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/8c72f0b2c45f21cb8b00fc37f79f632d7e46c2ed |
| https://git.kernel.org/stable/c/8a9d0d405159e9c796ddf771f7cff691c1a2bc1e |
| https://git.kernel.org/stable/c/e6a53481da292d970d1edf0d8831121d1c5e2f0d |
