futex: Adjust absolute futex timeouts with per time namespace offset

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: 5a590f3 ("posix-clocks: Wire up clock_gettime() with timens offsets") Reported-by: Hans van der Laan <[email protected]> Signed-off-by: Andrei Vagin <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Dmitry Safonov <[email protected]> Cc: <[email protected]> Link: https://lore.kernel.org/r/[email protected]
akvadrako · Oct 20, 2020 · c2f7d08 · c2f7d08
1 parent 270315b
commit c2f7d08
Showing 1 changed file with 5 additions and 0 deletions.
diff --git 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>
 
@@ -3797,6 +3798,8 @@ SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val,
 		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;
 	}
 	/*
@@ -3989,6 +3992,8 @@ SYSCALL_DEFINE6(futex_time32, u32 __user *, uaddr, int, op, u32, val,
 		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 ||