36 lines
1.5 KiB
Diff
36 lines
1.5 KiB
Diff
From: Sven Eckelmann <sven@narfation.org>
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Date: Mon, 31 Dec 2018 22:46:09 +0100
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Subject: batman-adv: Force mac header to start of data on xmit
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The caller of ndo_start_xmit may not already have called
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skb_reset_mac_header. The returned value of skb_mac_header/eth_hdr
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therefore can be in the wrong position and even outside the current skbuff.
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This for example happens when the user binds to the device using a
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PF_PACKET-SOCK_RAW with enabled qdisc-bypass:
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int opt = 4;
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setsockopt(sock, SOL_PACKET, PACKET_QDISC_BYPASS, &opt, sizeof(opt));
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Since eth_hdr is used all over the codebase, the batadv_interface_tx
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function must always take care of resetting it.
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Fixes: fe28a94c01e1 ("batman-adv: receive packets directly using skbs")
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Reported-by: syzbot+9d7405c7faa390e60b4e@syzkaller.appspotmail.com
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Reported-by: syzbot+7d20bc3f1ddddc0f9079@syzkaller.appspotmail.com
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Signed-off-by: Sven Eckelmann <sven@narfation.org>
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Origin: upstream, https://git.open-mesh.org/batman-adv.git/commit/74c4b0c50f19f986752ee18ed393732f4eed7a66
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diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
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index ff797f32fb3bb81dafe1e7d3e9c6307e6a5aaff1..f590c7b2c76816303fe1d3f5d2858e3a9b126539 100644
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--- a/net/batman-adv/soft-interface.c
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+++ b/net/batman-adv/soft-interface.c
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@@ -232,6 +232,8 @@ static int batadv_interface_tx(struct sk_buff *skb,
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netif_trans_update(soft_iface);
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vid = batadv_get_vid(skb, 0);
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+
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+ skb_reset_mac_header(skb);
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ethhdr = eth_hdr(skb);
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switch (ntohs(ethhdr->h_proto)) {
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