CVE-2024-46845

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> tracing/timerlat: Only clear timer if a kthread exists<br /> <br /> The timerlat tracer can use user space threads to check for osnoise and<br /> timer latency. If the program using this is killed via a SIGTERM, the<br /> threads are shutdown one at a time and another tracing instance can start<br /> up resetting the threads before they are fully closed. That causes the<br /> hrtimer assigned to the kthread to be shutdown and freed twice when the<br /> dying thread finally closes the file descriptors, causing a use-after-free<br /> bug.<br /> <br /> Only cancel the hrtimer if the associated thread is still around. Also add<br /> the interface_lock around the resetting of the tlat_var-&gt;kthread.<br /> <br /> Note, this is just a quick fix that can be backported to stable. A real<br /> fix is to have a better synchronization between the shutdown of old<br /> threads and the starting of new ones.