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| author | Álvaro Fernández Rojas <noltari@gmail.com> | 2017-04-23 13:55:03 +0200 |
|---|---|---|
| committer | Álvaro Fernández Rojas <noltari@gmail.com> | 2017-04-23 13:55:03 +0200 |
| commit | 1ab41265c39354332630bcba0ec704abd2e790f0 (patch) | |
| tree | 737495bb08b3562e272442dad1579df2bca57e1c /target/linux/generic/patches-4.4/030-1-smsc95xx-Use-skb_cow_head-to-deal-with-cloned-skbs.patch | |
| parent | 1d1935b242e2a2e5d34b2342b90eb772857e90bb (diff) | |
| download | upstream-1ab41265c39354332630bcba0ec704abd2e790f0.tar.gz upstream-1ab41265c39354332630bcba0ec704abd2e790f0.tar.bz2 upstream-1ab41265c39354332630bcba0ec704abd2e790f0.zip | |
kernel: use skb_cow_head() to deal with cloned skbs
We need to ensure there is enough headroom to push extra header,
but we also need to check if we are allowed to change headers.
skb_cow_head() is the proper helper to deal with this.
Fixes Ethernet<->WiFi bridge for Raspberry Pi and probably other devices.
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Diffstat (limited to 'target/linux/generic/patches-4.4/030-1-smsc95xx-Use-skb_cow_head-to-deal-with-cloned-skbs.patch')
| -rw-r--r-- | target/linux/generic/patches-4.4/030-1-smsc95xx-Use-skb_cow_head-to-deal-with-cloned-skbs.patch | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/target/linux/generic/patches-4.4/030-1-smsc95xx-Use-skb_cow_head-to-deal-with-cloned-skbs.patch b/target/linux/generic/patches-4.4/030-1-smsc95xx-Use-skb_cow_head-to-deal-with-cloned-skbs.patch new file mode 100644 index 0000000000..36fb936e32 --- /dev/null +++ b/target/linux/generic/patches-4.4/030-1-smsc95xx-Use-skb_cow_head-to-deal-with-cloned-skbs.patch @@ -0,0 +1,40 @@ +From e9156cd26a495a18706e796f02a81fee41ec14f4 Mon Sep 17 00:00:00 2001 +From: James Hughes <james.hughes@raspberrypi.org> +Date: Wed, 19 Apr 2017 11:13:40 +0100 +Subject: [PATCH] smsc95xx: Use skb_cow_head to deal with cloned skbs + +The driver was failing to check that the SKB wasn't cloned +before adding checksum data. +Replace existing handling to extend/copy the header buffer +with skb_cow_head. + +Signed-off-by: James Hughes <james.hughes@raspberrypi.org> +Acked-by: Eric Dumazet <edumazet@google.com> +Acked-by: Woojung Huh <Woojung.Huh@microchip.com> +Signed-off-by: David S. Miller <davem@davemloft.net> +--- + drivers/net/usb/smsc95xx.c | 12 ++++++------ + 1 file changed, 6 insertions(+), 6 deletions(-) + +--- a/drivers/net/usb/smsc95xx.c ++++ b/drivers/net/usb/smsc95xx.c +@@ -1835,13 +1835,13 @@ static struct sk_buff *smsc95xx_tx_fixup + /* We do not advertise SG, so skbs should be already linearized */ + BUG_ON(skb_shinfo(skb)->nr_frags); + +- if (skb_headroom(skb) < overhead) { +- struct sk_buff *skb2 = skb_copy_expand(skb, +- overhead, 0, flags); ++ /* Make writable and expand header space by overhead if required */ ++ if (skb_cow_head(skb, overhead)) { ++ /* Must deallocate here as returning NULL to indicate error ++ * means the skb won't be deallocated in the caller. ++ */ + dev_kfree_skb_any(skb); +- skb = skb2; +- if (!skb) +- return NULL; ++ return NULL; + } + + if (csum) { |