diff options
| author | Jakub Sitnicki <jkbs@redhat.com> | 2016-04-05 18:41:08 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-04-07 22:41:37 -0400 |
| commit | 3ba3458fb9c050718b95275a3310b74415e767e2 (patch) | |
| tree | a8b65c2b1408066207977d617ac7e4bcc620cc7b | |
| parent | 579ba855524c49d30929871b63c1f7637ffab4b6 (diff) | |
ipv6: Count in extension headers in skb->network_header
When sending a UDPv6 message longer than MTU, account for the length
of fragmentable IPv6 extension headers in skb->network_header offset.
Same as we do in alloc_new_skb path in __ip6_append_data().
This ensures that later on __ip6_make_skb() will make space in
headroom for fragmentable extension headers:
/* move skb->data to ip header from ext header */
if (skb->data < skb_network_header(skb))
__skb_pull(skb, skb_network_offset(skb));
Prevents a splat due to skb_under_panic:
skbuff: skb_under_panic: text:ffffffff8143397b len:2126 put:14 \
head:ffff880005bacf50 data:ffff880005bacf4a tail:0x48 end:0xc0 dev:lo
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:104!
invalid opcode: 0000 [#1] KASAN
CPU: 0 PID: 160 Comm: reproducer Not tainted 4.6.0-rc2 #65
[...]
Call Trace:
[<ffffffff813eb7b9>] skb_push+0x79/0x80
[<ffffffff8143397b>] eth_header+0x2b/0x100
[<ffffffff8141e0d0>] neigh_resolve_output+0x210/0x310
[<ffffffff814eab77>] ip6_finish_output2+0x4a7/0x7c0
[<ffffffff814efe3a>] ip6_output+0x16a/0x280
[<ffffffff815440c1>] ip6_local_out+0xb1/0xf0
[<ffffffff814f1115>] ip6_send_skb+0x45/0xd0
[<ffffffff81518836>] udp_v6_send_skb+0x246/0x5d0
[<ffffffff8151985e>] udpv6_sendmsg+0xa6e/0x1090
[...]
Reported-by: Ji Jianwen <jiji@redhat.com>
Signed-off-by: Jakub Sitnicki <jkbs@redhat.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/ipv6/ip6_output.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 9428345d3a07..bc972e7152c7 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -1090,8 +1090,8 @@ static inline int ip6_ufo_append_data(struct sock *sk, int getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb), void *from, int length, int hh_len, int fragheaderlen, - int transhdrlen, int mtu, unsigned int flags, - const struct flowi6 *fl6) + int exthdrlen, int transhdrlen, int mtu, + unsigned int flags, const struct flowi6 *fl6) { struct sk_buff *skb; @@ -1116,7 +1116,7 @@ static inline int ip6_ufo_append_data(struct sock *sk, skb_put(skb, fragheaderlen + transhdrlen); /* initialize network header pointer */ - skb_reset_network_header(skb); + skb_set_network_header(skb, exthdrlen); /* initialize protocol header pointer */ skb->transport_header = skb->network_header + fragheaderlen; @@ -1358,7 +1358,7 @@ emsgsize: (rt->dst.dev->features & NETIF_F_UFO) && (sk->sk_type == SOCK_DGRAM) && !udp_get_no_check6_tx(sk)) { err = ip6_ufo_append_data(sk, queue, getfrag, from, length, - hh_len, fragheaderlen, + hh_len, fragheaderlen, exthdrlen, transhdrlen, mtu, flags, fl6); if (err) goto error; |