From: Cong Wang <cong.wang@bytedance.com> [ Upstream commit 8621436671f3a4bba5db57482e1ee604708bf1eb ] syzbot is able to setup kTLS on an SMC socket which coincidentally uses sk_user_data too. Later, kTLS treats it as psock so triggers a refcnt warning. The root cause is that smc_setsockopt() simply calls TCP setsockopt() which includes TCP_ULP. I do not think it makes sense to setup kTLS on top of SMC sockets, so we should just disallow this setup. It is hard to find a commit to blame, but we can apply this patch since the beginning of TCP_ULP. Reported-and-tested-by: syzbot+b54a1ce86ba4a623b7f0@syzkaller.appspotmail.com Fixes: 734942cc4ea6 ("tcp: ULP infrastructure") Cc: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Cong Wang <cong.wang@bytedance.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- net/smc/af_smc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index 26dcd02b2d0ce..9aab4ab8161bd 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -1644,6 +1644,9 @@ static int smc_setsockopt(struct socket *sock, int level, int optname, struct smc_sock *smc; int val, rc; + if (level == SOL_TCP && optname == TCP_ULP) + return -EOPNOTSUPP; + smc = smc_sk(sk); /* generic setsockopts reaching us here always apply to the @@ -1665,7 +1668,6 @@ static int smc_setsockopt(struct socket *sock, int level, int optname, lock_sock(sk); switch (optname) { - case TCP_ULP: case TCP_FASTOPEN: case TCP_FASTOPEN_CONNECT: case TCP_FASTOPEN_KEY: -- 2.25.1