diff options
| author | Ben Hutchings <ben@decadent.org.uk> | 2015-04-15 19:00:32 +0100 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2015-04-22 08:58:32 +0200 |
| commit | 221ff9c56696e9e02d39ecb844528ebb4f8abf0f (patch) | |
| tree | ec3cfaa1277a8c96536d06dbc7292251423b3948 /net | |
| parent | 9647fcfbcad58f58edfa9f94aa691106ec29ff9a (diff) | |
tcp: Fix crash in TCP Fast Open
Commit 355a901e6cf1 ("tcp: make connect() mem charging friendly")
changed tcp_send_syn_data() to perform an open-coded copy of the 'syn'
skb rather than using skb_copy_expand().
The open-coded copy does not cover the skb_shared_info::gso_segs
field, so in the new skb it is left set to 0. When this commit was
backported into stable branches between 3.10.y and 3.16.7-ckty
inclusive, it triggered the BUG() in tcp_transmit_skb().
Since Linux 3.18 the GSO segment count is kept in the
tcp_skb_cb::tcp_gso_segs field and tcp_send_syn_data() does copy the
tcp_skb_cb structure to the new skb, so mainline and newer stable
branches are not affected.
Set skb_shared_info::gso_segs to the correct value of 1.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/tcp_output.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index e07ccba040be..56db79dbc633 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2919,6 +2919,7 @@ static int tcp_send_syn_data(struct sock *sk, struct sk_buff *syn) goto fallback; syn_data->ip_summed = CHECKSUM_PARTIAL; memcpy(syn_data->cb, syn->cb, sizeof(syn->cb)); + skb_shinfo(syn_data)->gso_segs = 1; if (unlikely(memcpy_fromiovecend(skb_put(syn_data, space), fo->data->msg_iov, 0, space))) { kfree_skb(syn_data); |