This is a note to let you know that I've just added the patch titled futex: Do not apply time namespace adjustment on FUTEX_LOCK_PI to the 5.12-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: futex-do-not-apply-time-namespace-adjustment-on-futex_lock_pi.patch and it can be found in the queue-5.12 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From cdf78db4070967869e4d027c11f4dd825d8f815a Mon Sep 17 00:00:00 2001 From: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Date: Thu, 22 Apr 2021 21:44:19 +0200 Subject: futex: Do not apply time namespace adjustment on FUTEX_LOCK_PI From: Thomas Gleixner <tglx@xxxxxxxxxxxxx> 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@xxxxxxxxxxxxx> Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Link: https://lore.kernel.org/r/20210422194704.984540159@xxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- kernel/futex.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/kernel/futex.c +++ b/kernel/futex.c @@ -3781,7 +3781,7 @@ 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; } @@ -3975,7 +3975,7 @@ 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; } Patches currently in stable-queue which might be from tglx@xxxxxxxxxxxxx are queue-5.12/posix-timers-preserve-return-value-in-clock_adjtime32.patch queue-5.12/futex-do-not-apply-time-namespace-adjustment-on-futex_lock_pi.patch queue-5.12/revert-337f13046ff0-futex-allow-futex_clock_realtime-with-futex_wait-op.patch queue-5.12/genirq-matrix-prevent-allocation-counter-corruption.patch queue-5.12/x86-cpu-initialize-msr_tsc_aux-if-rdtscp-or-rdpid-is-supported.patch