| From bippy-1.2.0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@kernel.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2025-22035: tracing: Fix use-after-free in print_graph_function_flags during tracer switching |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| tracing: Fix use-after-free in print_graph_function_flags during tracer switching |
| |
| Kairui reported a UAF issue in print_graph_function_flags() during |
| ftrace stress testing [1]. This issue can be reproduced if puting a |
| 'mdelay(10)' after 'mutex_unlock(&trace_types_lock)' in s_start(), |
| and executing the following script: |
| |
| $ echo function_graph > current_tracer |
| $ cat trace > /dev/null & |
| $ sleep 5 # Ensure the 'cat' reaches the 'mdelay(10)' point |
| $ echo timerlat > current_tracer |
| |
| The root cause lies in the two calls to print_graph_function_flags |
| within print_trace_line during each s_show(): |
| |
| * One through 'iter->trace->print_line()'; |
| * Another through 'event->funcs->trace()', which is hidden in |
| print_trace_fmt() before print_trace_line returns. |
| |
| Tracer switching only updates the former, while the latter continues |
| to use the print_line function of the old tracer, which in the script |
| above is print_graph_function_flags. |
| |
| Moreover, when switching from the 'function_graph' tracer to the |
| 'timerlat' tracer, s_start only calls graph_trace_close of the |
| 'function_graph' tracer to free 'iter->private', but does not set |
| it to NULL. This provides an opportunity for 'event->funcs->trace()' |
| to use an invalid 'iter->private'. |
| |
| To fix this issue, set 'iter->private' to NULL immediately after |
| freeing it in graph_trace_close(), ensuring that an invalid pointer |
| is not passed to other tracers. Additionally, clean up the unnecessary |
| 'iter->private = NULL' during each 'cat trace' when using wakeup and |
| irqsoff tracers. |
| |
| [1] https://lore.kernel.org/all/20231112150030.84609-1-ryncsn@gmail.com/ |
| |
| The Linux kernel CVE team has assigned CVE-2025-22035 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.4.255 with commit 05319d707732c728eb721ac616a50e7978eb499a and fixed in 5.4.292 with commit 42561fe62c3628ea3bc9623f64f047605e98857f |
| Issue introduced in 5.10.193 with commit b8205dfed68183dc1470e83863c5ded6d7fa30a9 and fixed in 5.10.236 with commit de7b309139f862a44379ecd96e93c9133c69f813 |
| Issue introduced in 5.15.129 with commit ce6e2b14bc094866d9173db6935da2d752f06d8b and fixed in 5.15.180 with commit 81a85b12132c8ffe98f5ddbdc185481790aeaa1b |
| Issue introduced in 6.1.50 with commit 2cb0c037c927db4ec928cc927488e52aa359786e and fixed in 6.1.134 with commit a2cce54c1748216535dda02e185d07a084be837e |
| Issue introduced in 6.5 with commit eecb91b9f98d6427d4af5fdb8f108f52572a39e7 and fixed in 6.6.87 with commit 099ef3385800828b74933a96c117574637c3fb3a |
| Issue introduced in 6.5 with commit eecb91b9f98d6427d4af5fdb8f108f52572a39e7 and fixed in 6.12.23 with commit c85efe6e13743cac6ba4ccf144cb91f44c86231a |
| Issue introduced in 6.5 with commit eecb91b9f98d6427d4af5fdb8f108f52572a39e7 and fixed in 6.13.11 with commit f14752d66056d0c7bffe5092130409417d3baa70 |
| Issue introduced in 6.5 with commit eecb91b9f98d6427d4af5fdb8f108f52572a39e7 and fixed in 6.14.2 with commit 70be951bc01e4a0e10d443f3510bb17426f257fb |
| Issue introduced in 6.5 with commit eecb91b9f98d6427d4af5fdb8f108f52572a39e7 and fixed in 6.15 with commit 7f81f27b1093e4895e87b74143c59c055c3b1906 |
| Issue introduced in 4.14.324 with commit d6b35c9a8d51032ed9890431da3ae39fe76c1ae3 |
| Issue introduced in 4.19.293 with commit 5d433eda76b66ab271f5924b26ddfec063eeb454 |
| Issue introduced in 6.4.13 with commit 2242640e9bd94e706acf75c60a2ab1d0e150e0fb |
| |
| 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-2025-22035 |
| 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_functions_graph.c |
| kernel/trace/trace_irqsoff.c |
| kernel/trace/trace_sched_wakeup.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/42561fe62c3628ea3bc9623f64f047605e98857f |
| https://git.kernel.org/stable/c/de7b309139f862a44379ecd96e93c9133c69f813 |
| https://git.kernel.org/stable/c/81a85b12132c8ffe98f5ddbdc185481790aeaa1b |
| https://git.kernel.org/stable/c/a2cce54c1748216535dda02e185d07a084be837e |
| https://git.kernel.org/stable/c/099ef3385800828b74933a96c117574637c3fb3a |
| https://git.kernel.org/stable/c/c85efe6e13743cac6ba4ccf144cb91f44c86231a |
| https://git.kernel.org/stable/c/f14752d66056d0c7bffe5092130409417d3baa70 |
| https://git.kernel.org/stable/c/70be951bc01e4a0e10d443f3510bb17426f257fb |
| https://git.kernel.org/stable/c/7f81f27b1093e4895e87b74143c59c055c3b1906 |
