| 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-2024-49976: tracing/timerlat: Drop interface_lock in stop_kthread() |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| tracing/timerlat: Drop interface_lock in stop_kthread() |
| |
| stop_kthread() is the offline callback for "trace/osnoise:online", since |
| commit 5bfbcd1ee57b ("tracing/timerlat: Add interface_lock around clearing |
| of kthread in stop_kthread()"), the following ABBA deadlock scenario is |
| introduced: |
| |
| T1 | T2 [BP] | T3 [AP] |
| osnoise_hotplug_workfn() | work_for_cpu_fn() | cpuhp_thread_fun() |
| | _cpu_down() | osnoise_cpu_die() |
| mutex_lock(&interface_lock) | | stop_kthread() |
| | cpus_write_lock() | mutex_lock(&interface_lock) |
| cpus_read_lock() | cpuhp_kick_ap() | |
| |
| As the interface_lock here in just for protecting the "kthread" field of |
| the osn_var, use xchg() instead to fix this issue. Also use |
| for_each_online_cpu() back in stop_per_cpu_kthreads() as it can take |
| cpu_read_lock() again. |
| |
| The Linux kernel CVE team has assigned CVE-2024-49976 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.6.51 with commit b4fdabffae14cca2c80d99bd81f3f27239ac7f5e and fixed in 6.6.55 with commit a4a05ceffe8fad68b45de38fe2311bda619e76e2 |
| Issue introduced in 6.10.10 with commit 4679272d5252720746fd9c5465352cbc5665f230 and fixed in 6.10.14 with commit 09cb44cc3d3df7ade2cebc939d6257a2fa8afc7a |
| Issue introduced in 6.11 with commit 5bfbcd1ee57b607fd29e4645c7f350dd385dd9ad and fixed in 6.11.3 with commit db8571a9a098086608c11a15856ff585789e67e8 |
| Issue introduced in 6.11 with commit 5bfbcd1ee57b607fd29e4645c7f350dd385dd9ad and fixed in 6.12 with commit b484a02c9cedf8703eff8f0756f94618004bd165 |
| |
| 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-2024-49976 |
| 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/a4a05ceffe8fad68b45de38fe2311bda619e76e2 |
| https://git.kernel.org/stable/c/09cb44cc3d3df7ade2cebc939d6257a2fa8afc7a |
| https://git.kernel.org/stable/c/db8571a9a098086608c11a15856ff585789e67e8 |
| https://git.kernel.org/stable/c/b484a02c9cedf8703eff8f0756f94618004bd165 |
