Patch "ntp: Fix integer overflow when setting time" has been added to the 3.3-stable tree

Patch "ntp: Fix integer overflow when setting time" has been added to the 3.3-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    ntp: Fix integer overflow when setting time

to the 3.3-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     ntp-fix-integer-overflow-when-setting-time.patch
and it can be found in the queue-3.3 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From a078c6d0e6288fad6d83fb6d5edd91ddb7b6ab33 Mon Sep 17 00:00:00 2001
From: Sasha Levin <levinsasha928@gmail.com>
Date: Thu, 15 Mar 2012 12:36:14 -0400
Subject: ntp: Fix integer overflow when setting time

From: Sasha Levin <levinsasha928@gmail.com>

commit a078c6d0e6288fad6d83fb6d5edd91ddb7b6ab33 upstream.

'long secs' is passed as divisor to div_s64, which accepts a 32bit
divisor. On 64bit machines that value is trimmed back from 8 bytes
back to 4, causing a divide by zero when the number is bigger than
(1 << 32) - 1 and all 32 lower bits are 0.

Use div64_long() instead.

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Cc: johnstul@us.ibm.com
Link: http://lkml.kernel.org/r/1331829374-31543-2-git-send-email-levinsasha928@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 kernel/time/ntp.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -275,7 +275,7 @@ static inline s64 ntp_update_offset_fll(
 
 	time_status |= STA_MODE;
 
-	return div_s64(offset64 << (NTP_SCALE_SHIFT - SHIFT_FLL), secs);
+	return div64_long(offset64 << (NTP_SCALE_SHIFT - SHIFT_FLL), secs);
 }
 
 static void ntp_update_offset(long offset)


Patches currently in stable-queue which might be from levinsasha928@gmail.com are

queue-3.3/math-introduce-div64_long.patch
queue-3.3/ntp-fix-integer-overflow-when-setting-time.patch