Commit 6f64ec74 authored Jun 27, 2017 by Eric Dumazet Committed by David S. Miller Jun 27, 2017

net: prevent sign extension in dev_get_stats()



Similar to the fix provided by Dominik Heidler in commit
9b3dc0a1 ("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: caf586e5 ("net: add a core netdev->rx_dropped counter")
Fixes: 015f0688 ("net: net: add a core netdev->tx_dropped counter")
Fixes: 6e7333d3 ("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>

parent d747a7a5

net/core/dev.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -7783,9 +7783,9 @@ struct rtnl_link_stats64 dev_get_stats(struct net_device dev,
		} 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_nohandler += atomic_long_read(&dev->rx_nohandler);
		storage->rx_dropped += (unsigned long)atomic_long_read(&dev->rx_dropped);
		storage->tx_dropped += (unsigned long)atomic_long_read(&dev->tx_dropped);
		storage->rx_nohandler += (unsigned long)atomic_long_read(&dev->rx_nohandler);
		return storage;
		}
		EXPORT_SYMBOL(dev_get_stats);

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