diff options
| author | Sven Eckelmann <sven@narfation.org> | 2018-12-31 22:31:01 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-02-15 08:07:39 +0100 |
| commit | 1474d65b85cfdb60aed3fdf095887f9d8232f121 (patch) | |
| tree | ac7681896606ce1abd1c92e37dc744c1f026c031 /net | |
| parent | a5a1ce4c3f088d13178a029327a1eb3452298957 (diff) | |
batman-adv: Force mac header to start of data on xmit
commit 9114daa825fc3f335f9bea3313ce667090187280 upstream.
The caller of ndo_start_xmit may not already have called
skb_reset_mac_header. The returned value of skb_mac_header/eth_hdr
therefore can be in the wrong position and even outside the current skbuff.
This for example happens when the user binds to the device using a
PF_PACKET-SOCK_RAW with enabled qdisc-bypass:
int opt = 4;
setsockopt(sock, SOL_PACKET, PACKET_QDISC_BYPASS, &opt, sizeof(opt));
Since eth_hdr is used all over the codebase, the batadv_interface_tx
function must always take care of resetting it.
Fixes: c6c8fea29769 ("net: Add batman-adv meshing protocol")
Reported-by: syzbot+9d7405c7faa390e60b4e@syzkaller.appspotmail.com
Reported-by: syzbot+7d20bc3f1ddddc0f9079@syzkaller.appspotmail.com
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/batman-adv/soft-interface.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c index 05bc176decf0..835af771a9fd 100644 --- a/net/batman-adv/soft-interface.c +++ b/net/batman-adv/soft-interface.c @@ -211,6 +211,8 @@ static int batadv_interface_tx(struct sk_buff *skb, netif_trans_update(soft_iface); vid = batadv_get_vid(skb, 0); + + skb_reset_mac_header(skb); ethhdr = eth_hdr(skb); switch (ntohs(ethhdr->h_proto)) { |