From: Hangyu Hua <hbh25y@gmail.com> stable inclusion from stable-v5.10.183 commit 7c5c67aa294444b53f697dc3ddce61b33ff8badd category: bugfix bugzilla: 188914 CVE: CVE-2023-35788 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit 4d56304e5827c8cc8cc18c75343d283af7c4825c ] If we send two TCA_FLOWER_KEY_ENC_OPTS_GENEVE packets and their total size is 252 bytes(key->enc_opts.len = 252) then key->enc_opts.len = opt->length = data_len / 4 = 0 when the third TCA_FLOWER_KEY_ENC_OPTS_GENEVE packet enters fl_set_geneve_opt. This bypasses the next bounds check and results in an out-of-bounds. Fixes: 0a6e77784f49 ("net/sched: allow flower to match tunnel options") Signed-off-by: Hangyu Hua <hbh25y@gmail.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Reviewed-by: Pieter Jansen van Vuuren <pieter.jansen-van-vuuren@amd.com> Link: https://lore.kernel.org/r/20230531102805.27090-1-hbh25y@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com> --- net/sched/cls_flower.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c index 8ff6945b9f8f..275122cc0b6d 100644 --- a/net/sched/cls_flower.c +++ b/net/sched/cls_flower.c @@ -1080,6 +1080,9 @@ static int fl_set_geneve_opt(const struct nlattr *nla, struct fl_flow_key *key, if (option_len > sizeof(struct geneve_opt)) data_len = option_len - sizeof(struct geneve_opt); + if (key->enc_opts.len > FLOW_DIS_TUN_OPTS_MAX - 4) + return -ERANGE; + opt = (struct geneve_opt *)&key->enc_opts.data[key->enc_opts.len]; memset(opt, 0xff, option_len); opt->length = data_len / 4; -- 2.34.1