From: Cong Wang <cong.wang@xxxxxxxxxxxxx>
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 cause is that smc_setsockopt() simply calls
TCP setsockopt(). I do not think it makes sense to setup kTLS on
top of SMC, so we can just disallow this.
Reported-and-tested-by: syzbot+b54a1ce86ba4a623b7f0@xxxxxxxxxxxxxxxxxxxxxxxxx
Cc: John Fastabend <john.fastabend@xxxxxxxxx>
Cc: Karsten Graul <kgraul@xxxxxxxxxxxxx>
Signed-off-by: Cong Wang <cong.wang@xxxxxxxxxxxxx>
---
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 47340b3b514f..0d4d6d28f20c 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -2162,6 +2162,9 @@ static int smc_setsockopt(struct socket *sock, int level, int optname,
struct smc_sock *smc;
int val, rc;
+ if (optname == TCP_ULP)
+ return -EOPNOTSUPP;
+
smc = smc_sk(sk);
/* generic setsockopts reaching us here always apply to the
@@ -2186,7 +2189,6 @@ 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:
--
2.25.1
