[PATCH net,v6,1/2] net/smc: modify smc_sock structure

Jeongjun Park
2024-08-20T12:15:33Z

Since inet_sk(sk)->pinet6 and smc_sk(sk)->clcsock practically
point to the same address, when smc_create_clcsk() stores the newly
created clcsock in smc_sk(sk)->clcsock, inet_sk(sk)->pinet6 is corrupted
into clcsock. This causes NULL pointer dereference and various other
memory corruptions.

To solve this, we need to modify the smc_sock structure.

Reported-by: syzkaller <syzkaller@googlegroups.com>
Fixes: ac7138746e14 ("smc: establish new socket family")
Signed-off-by: Jeongjun Park <aha310510@gmail.com>
---
net/smc/smc.h | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/net/smc/smc.h b/net/smc/smc.h
index 34b781e463c4..f23f76e94a66 100644
--- a/net/smc/smc.h
+++ b/net/smc/smc.h
@@ -283,7 +283,10 @@ struct smc_connection {
};

struct smc_sock { /* smc sock container */
- struct sock sk;
+ union {
+ struct sock sk; /* for AF_SMC */
+ struct inet_sock inet; /* for IPPROTO_SMC */
+ };
struct socket *clcsock; /* internal tcp socket */
void (*clcsk_state_change)(struct sock *sk);
/* original stat_change fct. */
--