On Tue, 04 Apr 2017 14:47:34 -0700 [email protected] wrote: > In PT_SEIZED + LISTEN mode STOP/CONT signals cause a wakeup against > __TASK_TRACED. If this races with the ptrace_unfreeze_traced at the end > of a PTRACE_LISTEN, this can wake the task /after/ the check against > __TASK_TRACED, but before the reset of state to TASK_TRACED. This causes > it to instead clobber TASK_WAKING, allowing a subsequent wakeup against > TRACED while the task is still on the rq wake_list, corrupting it.
The changelog doesn't convey the urgency of the fix. To understand this we'll need to know the user-visible impact of the bug and the likelihood of someone hitting it. Also your suggestion regarding which kernel version(s) should be fixed (and the reasoning) is always valuable.
