We need to make sure that the offset is valid before manipulating it,
otherwise it might overflow on the multiplication.
Signed-off-by: Sasha Levin <sasha.le...@oracle.com>
---
kernel/time/ntp.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index 149cc80..36616c3 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -297,6 +297,9 @@ static void ntp_update_offset(long offset)
if (!(time_status & STA_PLL))
return;
+ /* Make sure the multiplication below won't overflow */
+ offset = clamp(offset, -MAXPHASE, MAXPHASE);
+
if (!(time_status & STA_NANO))
offset *= NSEC_PER_USEC;
@@ -304,8 +307,7 @@ static void ntp_update_offset(long offset)
* Scale the phase adjustment and
* clamp to the operating range.
*/
- offset = min(offset, MAXPHASE);
- offset = max(offset, -MAXPHASE);
+ offset = clamp(offset, -MAXPHASE, MAXPHASE);
/*
* Select how the frequency is to be controlled
--
1.7.10.4
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
