net: fix harmonize_features() vs NETIF_F_HIGHDMA

[ Upstream commit 7be2c82cfd5d28d7adb66821a992604eb6dd112e ]

Ashizuka reported a highmem oddity and sent a patch for freescale
fec driver.

But the problem root cause is that core networking stack
must ensure no skb with highmem fragment is ever sent through
a device that does not assert NETIF_F_HIGHDMA in its features.

We need to call illegal_highdma() from harmonize_features()
regardless of CSUM checks.

Fixes: ec5f06156423 ("net: Kill link between CSUM and SG features.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Pravin Shelar <pshelar@ovn.org>
Reported-by: "Ashizuka, Yuusuke" <ashiduka@jp.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/core/dev.c b/net/core/dev.c
index 6f203c7fb1664116190ccb5847d47a5ddef76772..0798a0f1b39524af6cd9be4077ecba83e8c46d03 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2650,9 +2650,9 @@ static netdev_features_t harmonize_features(struct sk_buff *skb,
        if (skb->ip_summed != CHECKSUM_NONE &&
            !can_checksum_protocol(features, type)) {
                features &= ~NETIF_F_ALL_CSUM;
-       } else if (illegal_highdma(skb->dev, skb)) {
-               features &= ~NETIF_F_SG;
        }
+       if (illegal_highdma(skb->dev, skb))
+               features &= ~NETIF_F_SG;
 
        return features;
 }