ntp: Fix ADJ_SETOFFSET being used w/ ADJ_NANO

Recently, in commit 37cf4dc3370f I forgot to check if the timeval being passed
was actually a timespec (as is signaled with ADJ_NANO).

This resulted in that patch breaking ADJ_SETOFFSET users who set
ADJ_NANO, by rejecting valid timespecs that were compared with
valid timeval ranges.

This patch addresses this by checking for the ADJ_NANO flag and
using the timepsec check instead in that case.

Reported-by: Harald Hoyer <harald@redhat.com>
Reported-by: Kay Sievers <kay@vrfy.org>
Fixes: 37cf4dc3370f "time: Verify time values in adjtimex ADJ_SETOFFSET to avoid overflow"
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: David Herrmann <dh.herrmann@gmail.com>
Link: http://lkml.kernel.org/r/1453417415-19110-2-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 12 insertions, 2 deletions

diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index 36f2ca09aa5e..6df8927c58a5 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -685,8 +685,18 @@ int ntp_validate_timex(struct timex *txc)
                 if (!capable(CAP_SYS_TIME))
                         return -EPERM;
 
-                if (!timeval_inject_offset_valid(&txc->time))
-                        return -EINVAL;
+                if (txc->modes & ADJ_NANO) {
+                        struct timespec ts;
+
+                        ts.tv_sec = txc->time.tv_sec;
+                        ts.tv_nsec = txc->time.tv_usec;
+                        if (!timespec_inject_offset_valid(&ts))
+                                return -EINVAL;
+
+                } else {
+                        if (!timeval_inject_offset_valid(&txc->time))
+                                return -EINVAL;
+                }
         }
 
         /*