diff options
| author | Eric Dumazet <edumazet@google.com> | 2018-09-14 12:02:31 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-09-29 03:07:32 -0700 |
| commit | 76b338069f0dbf33ac7a66f167a804b9dcc96b58 (patch) | |
| tree | 4edf4b7f6eaeec1420f8f19b0bd7c8e00d9b2f8a | |
| parent | 2b797b65d8d9f1fc751e8bb3ef7a576f95895bda (diff) | |
ipv6: fix possible use-after-free in ip6_xmit()
[ Upstream commit bbd6528d28c1b8e80832b3b018ec402b6f5c3215 ]
In the unlikely case ip6_xmit() has to call skb_realloc_headroom(),
we need to call skb_set_owner_w() before consuming original skb,
otherwise we risk a use-after-free.
Bring IPv6 in line with what we do in IPv4 to fix this.
Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/ipv6/ip6_output.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index ea14466cdca8..8e77cecd2165 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -201,12 +201,10 @@ int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6, kfree_skb(skb); return -ENOBUFS; } + if (skb->sk) + skb_set_owner_w(skb2, skb->sk); consume_skb(skb); skb = skb2; - /* skb_set_owner_w() changes sk->sk_wmem_alloc atomically, - * it is safe to call in our context (socket lock not held) - */ - skb_set_owner_w(skb, (struct sock *)sk); } if (opt->opt_flen) ipv6_push_frag_opts(skb, opt, &proto); |