2db05cd199
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>
40 lines
1.4 KiB
Diff
40 lines
1.4 KiB
Diff
From e9156cd26a495a18706e796f02a81fee41ec14f4 Mon Sep 17 00:00:00 2001
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From: James Hughes <james.hughes@raspberrypi.org>
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Date: Wed, 19 Apr 2017 11:13:40 +0100
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Subject: [PATCH] smsc95xx: Use skb_cow_head to deal with cloned skbs
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The driver was failing to check that the SKB wasn't cloned
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before adding checksum data.
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Replace existing handling to extend/copy the header buffer
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with skb_cow_head.
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Signed-off-by: James Hughes <james.hughes@raspberrypi.org>
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Acked-by: Eric Dumazet <edumazet@google.com>
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Acked-by: Woojung Huh <Woojung.Huh@microchip.com>
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Signed-off-by: David S. Miller <davem@davemloft.net>
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---
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drivers/net/usb/smsc95xx.c | 12 ++++++------
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1 file changed, 6 insertions(+), 6 deletions(-)
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--- a/drivers/net/usb/smsc95xx.c
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+++ b/drivers/net/usb/smsc95xx.c
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@@ -2001,13 +2001,13 @@ static struct sk_buff *smsc95xx_tx_fixup
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/* We do not advertise SG, so skbs should be already linearized */
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BUG_ON(skb_shinfo(skb)->nr_frags);
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- if (skb_headroom(skb) < overhead) {
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- struct sk_buff *skb2 = skb_copy_expand(skb,
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- overhead, 0, flags);
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+ /* Make writable and expand header space by overhead if required */
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+ if (skb_cow_head(skb, overhead)) {
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+ /* Must deallocate here as returning NULL to indicate error
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+ * means the skb won't be deallocated in the caller.
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+ */
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dev_kfree_skb_any(skb);
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- skb = skb2;
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- if (!skb)
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- return NULL;
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+ return NULL;
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}
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if (csum) {
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