In the Linux kernel, the following vulnerability has been resolved: remoteproc: Prevent crash handling to race with rproc_del() There's no synchronization between rproc_crash_handler_work() and rproc_del(), as such it's possible for a driver to be removed while crash-handler work is scheduled, or even executing - resulting in use-after-free issues. To avoid this the scheduled work need to be cancelled and synchronized against before the removal proceeds. In order to ensure that this doesn't race with the reporting, and thereby scheduling new work, a "deleting" flag is introduced. This is similar to the RPROC_DELETE state that was introduced to ensure that "start" didn't race with rproc_del(), but the existing mechanism can not be used as it's valid to call rproc_report_crash() in atomic context - and the "state" is protected by a mutex. In the event that work is cancelled the pm_stay_awake() is left unbalanced and need to be unrolled. The blocking and cancelling of crash-handler work prior to the actual rproc_shutdown() call does have the explicit side-effect that crashes resulting from the shutdown process will not enter the crash-handling path, and as such will not generate devcoredumps etc. Due to the existing mutual exclusion between these code paths there's no concrete reduction in functionality, but further work would be needed to handle this case.
https://git.kernel.org/stable/c/f15cde11298402f803d5dda9cb9f95eea3d2ca40
https://git.kernel.org/stable/c/a8a62cb4d2f3fd6aa06e86f1711c62d2a4cf17d5
https://git.kernel.org/stable/c/a31d9562eeec5c4103c202fc87651f6e7d3d0035
https://git.kernel.org/stable/c/74ee3b2f5767447c57959994341e5b95f1079977
https://git.kernel.org/stable/c/69af36f1fb7d24d287662fef6b2093bcf847a9db
https://git.kernel.org/stable/c/61862ed651b2493573e6d2192d5640bc6616f5d0
https://git.kernel.org/stable/c/50f232c26298923d39a48dc8e03d1732e5a5dcf1
https://git.kernel.org/stable/c/47de033918cd772146f7438aa04471c020b2dedc