4.19.94-rt39-rc1 stable review patch. If anyone has any objections, please let me know. ------------------ From: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> [ Upstream commit 356a2781375ec58521a9bc3f500488745990c242 ] Patch ("posix-timers: Add expiry lock") acquired a lock in run_posix_cpu_timers() but didn't drop the lock in the early return. Unlock the lock in the early return path. Reported-by: kbuild test robot <lkp@xxxxxxxxx> Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx> --- kernel/time/posix-cpu-timers.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c index 765e700962ab..c9964dc3276b 100644 --- a/kernel/time/posix-cpu-timers.c +++ b/kernel/time/posix-cpu-timers.c @@ -1175,8 +1175,10 @@ static void __run_posix_cpu_timers(struct task_struct *tsk) expiry_lock = this_cpu_ptr(&cpu_timer_expiry_lock); spin_lock(expiry_lock); - if (!lock_task_sighand(tsk, &flags)) + if (!lock_task_sighand(tsk, &flags)) { + spin_unlock(expiry_lock); return; + } /* * Here we take off tsk->signal->cpu_timers[N] and * tsk->cpu_timers[N] all the timers that are firing, and -- 2.24.1