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| author | MoYuanhao <moyuanhao3676@163.com> | 2024-12-09 13:28:14 +0100 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-12-10 18:26:52 -0800 |
| commit | 06d64ab46f19ac12f59a1d2aa8cd196b2e4edb5b (patch) | |
| tree | f5870d0869d99786ea8fd9f0c5dd8e0fe6f71f37 | |
| parent | bbe4b41259a3e255a16d795486d331c1670b4e75 (diff) | |
| download | linux-stable-06d64ab46f19ac12f59a1d2aa8cd196b2e4edb5b.tar.gz linux-stable-06d64ab46f19ac12f59a1d2aa8cd196b2e4edb5b.tar.bz2 linux-stable-06d64ab46f19ac12f59a1d2aa8cd196b2e4edb5b.zip | |
tcp: check space before adding MPTCP SYN options
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>
| -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 5485a70b5fe5..0e5b9a654254 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; + } } } |