CVE-2025-22035

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/[email protected]/

• linux linux kernel (>= 4.14.324 < 4.15) • linux linux kernel (>= 4.19.293 < 4.20) • linux linux kernel (>= 5.4.255 < 5.4.292) • linux linux kernel (>= 5.10.193 < 5.10.236) • linux linux kernel (>= 5.15.129 < 5.15.180) • linux linux kernel (>= 6.1.50 < 6.1.134) • linux linux kernel (>= 6.4.13 < 6.6.87) • linux linux kernel (>= 6.7 < 6.12.23) • linux linux kernel (>= 6.13 < 6.13.11) • linux linux kernel (>= 6.14 < 6.14.2)