{"id":"CVE-2025-22035","summary":"tracing: Fix use-after-free in print_graph_function_flags during tracer switching","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Fix use-after-free in print_graph_function_flags during tracer switching\n\nKairui reported a UAF issue in print_graph_function_flags() during\nftrace stress testing [1]. This issue can be reproduced if puting a\n'mdelay(10)' after 'mutex_unlock(&trace_types_lock)' in s_start(),\nand executing the following script:\n\n  $ echo function_graph \u003e current_tracer\n  $ cat trace \u003e /dev/null &\n  $ sleep 5  # Ensure the 'cat' reaches the 'mdelay(10)' point\n  $ echo timerlat \u003e current_tracer\n\nThe root cause lies in the two calls to print_graph_function_flags\nwithin print_trace_line during each s_show():\n\n  * One through 'iter-\u003etrace-\u003eprint_line()';\n  * Another through 'event-\u003efuncs-\u003etrace()', which is hidden in\n    print_trace_fmt() before print_trace_line returns.\n\nTracer switching only updates the former, while the latter continues\nto use the print_line function of the old tracer, which in the script\nabove is print_graph_function_flags.\n\nMoreover, when switching from the 'function_graph' tracer to the\n'timerlat' tracer, s_start only calls graph_trace_close of the\n'function_graph' tracer to free 'iter-\u003eprivate', but does not set\nit to NULL. This provides an opportunity for 'event-\u003efuncs-\u003etrace()'\nto use an invalid 'iter-\u003eprivate'.\n\nTo fix this issue, set 'iter-\u003eprivate' to NULL immediately after\nfreeing it in graph_trace_close(), ensuring that an invalid pointer\nis not passed to other tracers. Additionally, clean up the unnecessary\n'iter-\u003eprivate = NULL' during each 'cat trace' when using wakeup and\nirqsoff tracers.\n\n [1] https://lore.kernel.org/all/20231112150030.84609-1-ryncsn@gmail.com/","modified":"2026-04-16T04:38:34.970749846Z","published":"2025-04-16T14:11:53.958Z","related":["SUSE-SU-2025:02249-1","SUSE-SU-2025:02254-1","SUSE-SU-2025:02307-1","SUSE-SU-2025:02333-1","SUSE-SU-2025:02334-1","SUSE-SU-2025:02335-1","SUSE-SU-2025:02538-1","SUSE-SU-2025:02923-1","SUSE-SU-2025:20475-1","SUSE-SU-2025:20483-1","SUSE-SU-2025:20493-1","SUSE-SU-2025:20498-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/22xxx/CVE-2025-22035.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/099ef3385800828b74933a96c117574637c3fb3a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/42561fe62c3628ea3bc9623f64f047605e98857f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/70be951bc01e4a0e10d443f3510bb17426f257fb"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7f81f27b1093e4895e87b74143c59c055c3b1906"},{"type":"WEB","url":"https://git.kernel.org/stable/c/81a85b12132c8ffe98f5ddbdc185481790aeaa1b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a2cce54c1748216535dda02e185d07a084be837e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c85efe6e13743cac6ba4ccf144cb91f44c86231a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/de7b309139f862a44379ecd96e93c9133c69f813"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f14752d66056d0c7bffe5092130409417d3baa70"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/22xxx/CVE-2025-22035.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-22035"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"05319d707732c728eb721ac616a50e7978eb499a"},{"fixed":"42561fe62c3628ea3bc9623f64f047605e98857f"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"b8205dfed68183dc1470e83863c5ded6d7fa30a9"},{"fixed":"de7b309139f862a44379ecd96e93c9133c69f813"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"ce6e2b14bc094866d9173db6935da2d752f06d8b"},{"fixed":"81a85b12132c8ffe98f5ddbdc185481790aeaa1b"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"2cb0c037c927db4ec928cc927488e52aa359786e"},{"fixed":"a2cce54c1748216535dda02e185d07a084be837e"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"eecb91b9f98d6427d4af5fdb8f108f52572a39e7"},{"fixed":"099ef3385800828b74933a96c117574637c3fb3a"},{"fixed":"c85efe6e13743cac6ba4ccf144cb91f44c86231a"},{"fixed":"f14752d66056d0c7bffe5092130409417d3baa70"},{"fixed":"70be951bc01e4a0e10d443f3510bb17426f257fb"},{"fixed":"7f81f27b1093e4895e87b74143c59c055c3b1906"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"0"},{"last_affected":"d6b35c9a8d51032ed9890431da3ae39fe76c1ae3"},{"last_affected":"5d433eda76b66ab271f5924b26ddfec063eeb454"},{"last_affected":"2242640e9bd94e706acf75c60a2ab1d0e150e0fb"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-22035.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}