Patch "net: prevent sign extension in dev_get_stats()" has been added to the 4.4-stable tree

Patch "net: prevent sign extension in dev_get_stats()" has been added to the 4.4-stable tree

[gregkh]

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

    net: prevent sign extension in dev_get_stats()

to the 4.4-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:
     net-prevent-sign-extension-in-dev_get_stats.patch
and it can be found in the queue-4.4 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 6f64ec74515925cced6df4571638b5a099a49aae Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet@google.com>
Date: Tue, 27 Jun 2017 07:02:20 -0700
Subject: net: prevent sign extension in dev_get_stats()

From: Eric Dumazet <edumazet@google.com>

commit 6f64ec74515925cced6df4571638b5a099a49aae upstream.

Similar to the fix provided by Dominik Heidler in commit
9b3dc0a17d73 ("l2tp: cast l2tp traffic counter to unsigned")
we need to take care of 32bit kernels in dev_get_stats().

When using atomic_long_read(), we add a 'long' to u64 and
might misinterpret high order bit, unless we cast to unsigned.

Fixes: caf586e5f23ce ("net: add a core netdev->rx_dropped counter")
Fixes: 015f0688f57ca ("net: net: add a core netdev->tx_dropped counter")
Fixes: 6e7333d315a76 ("net: add rx_nohandler stat counter")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jarod Wilson <jarod@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 net/core/dev.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -7052,8 +7052,8 @@ struct rtnl_link_stats64 *dev_get_stats(
 	} else {
 		netdev_stats_to_stats64(storage, &dev->stats);
 	}
-	storage->rx_dropped += atomic_long_read(&dev->rx_dropped);
-	storage->tx_dropped += atomic_long_read(&dev->tx_dropped);
+	storage->rx_dropped += (unsigned long)atomic_long_read(&dev->rx_dropped);
+	storage->tx_dropped += (unsigned long)atomic_long_read(&dev->tx_dropped);
 	return storage;
 }
 EXPORT_SYMBOL(dev_get_stats);


Patches currently in stable-queue which might be from edumazet@google.com are

queue-4.4/net-sched-fix-one-possible-panic-when-no-destroy-callback.patch
queue-4.4/net-prevent-sign-extension-in-dev_get_stats.patch
queue-4.4/net_sched-fix-error-recovery-at-qdisc-creation.patch