From: Maxim Mikityanskiy maximmi@nvidia.com
[ Upstream commit 07718be265680dcf496347d475ce1a5442f55ad7 ]
The TCP option parser in mptcp (mptcp_get_options) could read one byte out of bounds. When the length is 1, the execution flow gets into the loop, reads one byte of the opcode, and if the opcode is neither TCPOPT_EOL nor TCPOPT_NOP, it reads one more byte, which exceeds the length of 1.
This fix is inspired by commit 9609dad263f8 ("ipv4: tcp_input: fix stack out of bounds when parsing TCP options.").
Cc: Young Xiao 92siuyang@gmail.com Fixes: cec37a6e41aa ("mptcp: Handle MP_CAPABLE options for outgoing connections") Signed-off-by: Maxim Mikityanskiy maximmi@nvidia.com Reviewed-by: Mat Martineau mathew.j.martineau@linux.intel.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/mptcp/options.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/net/mptcp/options.c b/net/mptcp/options.c index 91034a221983..ac0233c9cd34 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -314,6 +314,8 @@ void mptcp_get_options(const struct sk_buff *skb, length--; continue; default: + if (length < 2) + return; opsize = *ptr++; if (opsize < 2) /* "silly options" */ return;