| From 9a644e8397d1aa64fb84431112faab1419fcb2bd Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Wed, 5 May 2021 12:40:48 -0700 |
| Subject: smc: disallow TCP_ULP in smc_setsockopt() |
| |
| 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> |
| --- |
| 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 5dd4faaf7d6e..030d7f30b13f 100644 |
| --- a/net/smc/af_smc.c |
| +++ b/net/smc/af_smc.c |
| @@ -2147,6 +2147,9 @@ 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 |
| @@ -2171,7 +2174,6 @@ static int smc_setsockopt(struct socket *sock, int level, int optname, |
| if (rc || smc->use_fallback) |
| goto out; |
| switch (optname) { |
| - case TCP_ULP: |
| case TCP_FASTOPEN: |
| case TCP_FASTOPEN_CONNECT: |
| case TCP_FASTOPEN_KEY: |
| -- |
| 2.30.2 |
| |