diff options
| author | MoYuanhao <moyuanhao3676@163.com> | 2024-12-09 13:28:14 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-12-19 18:12:59 +0100 |
| commit | 8aa9d1ff5b7fe191517d0d794bb3ad1f2ca977ad (patch) | |
| tree | eec5e8653ca315d4976ef382301b0dad44a13213 /net/ipv4/tcp_output.c | |
| parent | 26702b3439f56ebcafe984ebabe51a40058a467e (diff) | |
tcp: check space before adding MPTCP SYN options
commit 06d64ab46f19ac12f59a1d2aa8cd196b2e4edb5b upstream.
Ensure there is enough space before adding MPTCP options in
tcp_syn_options().
Without this check, 'remaining' could underflow, and causes issues. If
there is not enough space, MPTCP should not be used.
Signed-off-by: MoYuanhao <moyuanhao3676@163.com>
Fixes: cec37a6e41aa ("mptcp: Handle MP_CAPABLE options for outgoing connections")
Cc: stable@vger.kernel.org
Acked-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
[ Matt: Add Fixes, cc Stable, update Description ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241209-net-mptcp-check-space-syn-v1-1-2da992bb6f74@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/ipv4/tcp_output.c')
| -rw-r--r-- | net/ipv4/tcp_output.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 68804fd01daf..8efc58716ce9 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -883,8 +883,10 @@ static unsigned int tcp_syn_options(struct sock *sk, struct sk_buff *skb, unsigned int size; if (mptcp_syn_options(sk, skb, &size, &opts->mptcp)) { - opts->options |= OPTION_MPTCP; - remaining -= size; + if (remaining >= size) { + opts->options |= OPTION_MPTCP; + remaining -= size; + } } } |