[PATCH 4.9 19/51] net: fix harmonize_features() vs NETIF_F_HIGHDMA

From: Greg Kroah-Hartman
Date: Thu Feb 02 2017 - 13:38:50 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Eric Dumazet <edumazet@xxxxxxxxxx>


[ 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@xxxxxxxxxx>
Cc: Pravin Shelar <pshelar@xxxxxxx>
Reported-by: "Ashizuka, Yuusuke" <ashiduka@xxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/core/dev.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2815,9 +2815,9 @@ static netdev_features_t harmonize_featu
if (skb->ip_summed != CHECKSUM_NONE &&
!can_checksum_protocol(features, type)) {
features &= ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
- } else if (illegal_highdma(skb->dev, skb)) {
- features &= ~NETIF_F_SG;
}
+ if (illegal_highdma(skb->dev, skb))
+ features &= ~NETIF_F_SG;

return features;
}