Since smc_inet6_prot does not initialize ipv6_pinfo_offset, inet6_create()
copies an incorrect address value, sk + 0 (offset), to inet_sk(sk)->pinet6.
In addition, 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 add a smc6_sock structure for ipv6_pinfo_offset
initialization and modify the smc_sock structure.
Reported-by: syzbot+f69bfae0a4eb29976e44@xxxxxxxxxxxxxxxxxxxxxxxxx
Tested-by: syzbot+f69bfae0a4eb29976e44@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: d25a92ccae6b ("net/smc: Introduce IPPROTO_SMC")
Signed-off-by: Jeongjun Park <aha310510@xxxxxxxxx>
---
net/smc/smc.h | 19 ++++++++++---------
net/smc/smc_inet.c | 24 +++++++++++++++---------
2 files changed, 25 insertions(+), 18 deletions(-)
diff --git a/net/smc/smc.h b/net/smc/smc.h
index 34b781e463c4..f4d9338b5ed5 100644
--- a/net/smc/smc.h
+++ b/net/smc/smc.h
@@ -284,15 +284,6 @@ struct smc_connection {
struct smc_sock { /* smc sock container */
struct sock sk;
- struct socket *clcsock; /* internal tcp socket */
- void (*clcsk_state_change)(struct sock *sk);
- /* original stat_change fct. */
- void (*clcsk_data_ready)(struct sock *sk);
- /* original data_ready fct. */
- void (*clcsk_write_space)(struct sock *sk);
- /* original write_space fct. */
- void (*clcsk_error_report)(struct sock *sk);
- /* original error_report fct. */
struct smc_connection conn; /* smc connection */
struct smc_sock *listen_smc; /* listen parent */
struct work_struct connect_work; /* handle non-blocking connect*/
@@ -325,6 +316,16 @@ struct smc_sock { /* smc sock container */
/* protects clcsock of a listen
* socket
* */
+ struct socket *clcsock; /* internal tcp socket */
+ void (*clcsk_state_change)(struct sock *sk);
+ /* original stat_change fct. */
+ void (*clcsk_data_ready)(struct sock *sk);
+ /* original data_ready fct. */
+ void (*clcsk_write_space)(struct sock *sk);
+ /* original write_space fct. */
+ void (*clcsk_error_report)(struct sock *sk);
+ /* original error_report fct. */
+
};
#define smc_sk(ptr) container_of_const(ptr, struct smc_sock, sk)
diff --git a/net/smc/smc_inet.c b/net/smc/smc_inet.c
index bece346dd8e9..25f34fd65e8d 100644
--- a/net/smc/smc_inet.c
+++ b/net/smc/smc_inet.c
@@ -60,16 +60,22 @@ static struct inet_protosw smc_inet_protosw = {
};
#if IS_ENABLED(CONFIG_IPV6)
+struct smc6_sock {
+ struct smc_sock smc;
+ struct ipv6_pinfo np;
+};
+
static struct proto smc_inet6_prot = {
- .name = "INET6_SMC",
- .owner = THIS_MODULE,
- .init = smc_inet_init_sock,
- .hash = smc_hash_sk,
- .unhash = smc_unhash_sk,
- .release_cb = smc_release_cb,
- .obj_size = sizeof(struct smc_sock),
- .h.smc_hash = &smc_v6_hashinfo,
- .slab_flags = SLAB_TYPESAFE_BY_RCU,
+ .name = "INET6_SMC",
+ .owner = THIS_MODULE,
+ .init = smc_inet_init_sock,
+ .hash = smc_hash_sk,
+ .unhash = smc_unhash_sk,
+ .release_cb = smc_release_cb,
+ .obj_size = sizeof(struct smc6_sock),
+ .h.smc_hash = &smc_v6_hashinfo,
+ .slab_flags = SLAB_TYPESAFE_BY_RCU,
+ .ipv6_pinfo_offset = offsetof(struct smc6_sock, np),
};
static const struct proto_ops smc_inet6_stream_ops = {
--
