CVE-2025-22035

Summary

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/

Affected Software

VendorProductVersion RangeStatus
LinuxLinux05319d707732c728eb721ac616a50e7978eb499a < 42561fe62c3628ea3bc9623f64f047605e98857faffected
LinuxLinuxb8205dfed68183dc1470e83863c5ded6d7fa30a9 < de7b309139f862a44379ecd96e93c9133c69f813affected
LinuxLinuxce6e2b14bc094866d9173db6935da2d752f06d8b < 81a85b12132c8ffe98f5ddbdc185481790aeaa1baffected
LinuxLinux2cb0c037c927db4ec928cc927488e52aa359786e < a2cce54c1748216535dda02e185d07a084be837eaffected
LinuxLinuxeecb91b9f98d6427d4af5fdb8f108f52572a39e7 < 099ef3385800828b74933a96c117574637c3fb3aaffected
LinuxLinuxeecb91b9f98d6427d4af5fdb8f108f52572a39e7 < c85efe6e13743cac6ba4ccf144cb91f44c86231aaffected
LinuxLinuxeecb91b9f98d6427d4af5fdb8f108f52572a39e7 < f14752d66056d0c7bffe5092130409417d3baa70affected
LinuxLinuxeecb91b9f98d6427d4af5fdb8f108f52572a39e7 < 70be951bc01e4a0e10d443f3510bb17426f257fbaffected
LinuxLinuxeecb91b9f98d6427d4af5fdb8f108f52572a39e7 < 7f81f27b1093e4895e87b74143c59c055c3b1906affected
LinuxLinuxd6b35c9a8d51032ed9890431da3ae39fe76c1ae3affected
LinuxLinux5d433eda76b66ab271f5924b26ddfec063eeb454affected
LinuxLinux2242640e9bd94e706acf75c60a2ab1d0e150e0fbaffected
LinuxLinux5.4.255 < 5.4.292affected
LinuxLinux5.10.193 < 5.10.236affected
LinuxLinux5.15.129 < 5.15.180affected
LinuxLinux6.1.50 < 6.1.134affected
LinuxLinux4.14.324 < 4.15affected
LinuxLinux4.19.293 < 4.20affected
LinuxLinux6.4.13 < 6.5affected
LinuxLinux6.5affected
LinuxLinux0 < 6.5unaffected
LinuxLinux5.4.292 <= 5.4.*unaffected
LinuxLinux5.10.236 <= 5.10.*unaffected
LinuxLinux5.15.180 <= 5.15.*unaffected
LinuxLinux6.1.134 <= 6.1.*unaffected
LinuxLinux6.6.87 <= 6.6.*unaffected
LinuxLinux6.12.23 <= 6.12.*unaffected
LinuxLinux6.13.11 <= 6.13.*unaffected
LinuxLinux6.14.2 <= 6.14.*unaffected
LinuxLinux6.15 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: total

CVE Program Container

Additional References

References