From: Andrei Vagin <avagin@xxxxxxxxx>
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@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrei Vagin <avagin@xxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Dmitry Safonov <0x7f454c46@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20201015160020.293748-1-avagin@xxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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 ||
