[ Upstream commit 735ee8582d ]
Quoting reporter:
In net/netfilter/xt_tcpmss.c (lines 53-68), the TCP option parser reads
op[i+1] directly without validating the remaining option length.
If the last byte of the option field is not EOL/NOP (0/1), the code attempts
to index op[i+1]. In the case where i + 1 == optlen, this causes an
out-of-bounds read, accessing memory past the optlen boundary
(either reading beyond the stack buffer _opt or the
following payload).
Reported-by: sungzii <sungzii@pm.me>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Florian WestphalandSasha Levin
07a9b32eaa