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authorWillem de Bruijn <willemb@google.com>2018-07-11 19:00:45 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-08-24 14:12:39 +0300
commit4770fdc633650794717f5f1c2011a8c570e09cce (patch)
tree3be1ad3a488a1acc3dd5ee2755625fe0d846f4ab
parentfaf0464e333010ecc3c4214e7942633d9f761296 (diff)
downloadlinux-4770fdc633650794717f5f1c2011a8c570e09cce.tar.xz
packet: reset network header if packet shorter than ll reserved space
[ Upstream commit 993675a3100b16a4c80dfd70cbcde8ea7127b31d ] If variable length link layer headers result in a packet shorter than dev->hard_header_len, reset the network header offset. Else skb->mac_len may exceed skb->len after skb_mac_reset_len. packet_sendmsg_spkt already has similar logic. Fixes: b84bbaf7a6c8 ("packet: in packet_snd start writing at link layer allocation") Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--net/packet/af_packet.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index ea601f7ca2f8..61eec3e9ef66 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -2917,6 +2917,8 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
goto out_free;
} else if (reserve) {
skb_reserve(skb, -reserve);
+ if (len < reserve)
+ skb_reset_network_header(skb);
}
/* Returns -EFAULT on error */