| From c2f7d08cccf4af2ce6992feaabb9e68e4ae0bff3 Mon Sep 17 00:00:00 2001 |
| From: Andrei Vagin <avagin@gmail.com> |
| Date: Thu, 15 Oct 2020 09:00:19 -0700 |
| Subject: futex: Adjust absolute futex timeouts with per time namespace offset |
| |
| From: Andrei Vagin <avagin@gmail.com> |
| |
| commit c2f7d08cccf4af2ce6992feaabb9e68e4ae0bff3 upstream. |
| |
| For all commands except FUTEX_WAIT, the timeout is interpreted as an |
| absolute value. This absolute value is inside the task's time namespace and |
| has to be converted to the host's time. |
| |
| Fixes: 5a590f35add9 ("posix-clocks: Wire up clock_gettime() with timens offsets") |
| Reported-by: Hans van der Laan <j.h.vanderlaan@student.utwente.nl> |
| Signed-off-by: Andrei Vagin <avagin@gmail.com> |
| Signed-off-by: Thomas Gleixner <tglx@linutronix.de> |
| Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com> |
| Cc: <stable@vger.kernel.org> |
| Link: https://lore.kernel.org/r/20201015160020.293748-1-avagin@gmail.com |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| kernel/futex.c | 5 +++++ |
| 1 file changed, 5 insertions(+) |
| |
| --- a/kernel/futex.c |
| +++ b/kernel/futex.c |
| @@ -39,6 +39,7 @@ |
| #include <linux/freezer.h> |
| #include <linux/memblock.h> |
| #include <linux/fault-inject.h> |
| +#include <linux/time_namespace.h> |
| |
| #include <asm/futex.h> |
| |
| @@ -3799,6 +3800,8 @@ 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)) |
| + t = timens_ktime_to_host(CLOCK_MONOTONIC, t); |
| tp = &t; |
| } |
| /* |
| @@ -3991,6 +3994,8 @@ 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)) |
| + t = timens_ktime_to_host(CLOCK_MONOTONIC, t); |
| tp = &t; |
| } |
| if (cmd == FUTEX_REQUEUE || cmd == FUTEX_CMP_REQUEUE || |