From: Thomas Gleixner tglx@linutronix.de
commit cdf78db4070967869e4d027c11f4dd825d8f815a upstream.
FUTEX_LOCK_PI does not require to have the FUTEX_CLOCK_REALTIME bit set because it has been using CLOCK_REALTIME based absolute timeouts forever. Due to that, the time namespace adjustment which is applied when FUTEX_CLOCK_REALTIME is not set, will wrongly take place for FUTEX_LOCK_PI and wreckage the timeout.
Exclude it from that procedure.
Fixes: c2f7d08cccf4 ("futex: Adjust absolute futex timeouts with per time namespace offset") Signed-off-by: Thomas Gleixner tglx@linutronix.de Acked-by: Peter Zijlstra (Intel) peterz@infradead.org Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210422194704.984540159@linutronix.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- kernel/futex.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/kernel/futex.c +++ b/kernel/futex.c @@ -3782,7 +3782,7 @@ SYSCALL_DEFINE6(futex, u32 __user *, uad t = timespec64_to_ktime(ts); if (cmd == FUTEX_WAIT) t = ktime_add_safe(ktime_get(), t); - else if (!(op & FUTEX_CLOCK_REALTIME)) + else if (cmd != FUTEX_LOCK_PI && !(op & FUTEX_CLOCK_REALTIME)) t = timens_ktime_to_host(CLOCK_MONOTONIC, t); tp = &t; } @@ -3976,7 +3976,7 @@ SYSCALL_DEFINE6(futex_time32, u32 __user t = timespec64_to_ktime(ts); if (cmd == FUTEX_WAIT) t = ktime_add_safe(ktime_get(), t); - else if (!(op & FUTEX_CLOCK_REALTIME)) + else if (cmd != FUTEX_LOCK_PI && !(op & FUTEX_CLOCK_REALTIME)) t = timens_ktime_to_host(CLOCK_MONOTONIC, t); tp = &t; }