published May 30, 2024
In the Linux kernel, the following vulnerability has been resolved:
thermal/debugfs: Prevent use-after-free from occurring after cdev removal
Since thermal_debug_cdev_remove() does not run under cdev->lock, it can
run in parallel with thermal_debug_cdev_state_update() and it may free
the struct thermal_debugfs object used by the latter after it has been
checked against NULL.
If that happens, thermal_debug_cdev_state_update() will access memory
that has been freed already causing the kernel to crash.
Address this by using cdev->lock in thermal_debug_cdev_remove() around
the cdev->debugfs value check (in case the same cdev is removed at the
same time in two different threads) and its reset to NULL.
Cc :6.8+ <[email protected]> # 6.8+