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authorMaxim Mikityanskiy <maximmi@nvidia.com>2021-06-10 19:40:30 +0300
committerDavid S. Miller <davem@davemloft.net>2021-06-10 14:26:18 -0700
commit07718be265680dcf496347d475ce1a5442f55ad7 (patch)
treed708cf35e5b0becfc985b668ae5edc357dd66700
parent5fc177ab759418c9537433e63301096e733fb915 (diff)
mptcp: Fix out of bounds when parsing TCP options
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>
-rw-r--r--net/mptcp/options.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 6b825fb3fa83..9b263f27ce9b 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -356,6 +356,8 @@ void mptcp_get_options(const struct sk_buff *skb,
length--;
continue;
default:
+ if (length < 2)
+ return;
opsize = *ptr++;
if (opsize < 2) /* "silly options" */
return;