Commit 78abe3d0 authored by Myungho Jung's avatar Myungho Jung Committed by David S. Miller

net/smc: fix TCP fallback socket release

clcsock can be released while kernel_accept() references it in TCP
listen worker. Also, clcsock needs to wake up before released if TCP
fallback is used and the clcsock is blocked by accept. Add a lock to
safely release clcsock and call kernel_sock_shutdown() to wake up
clcsock from accept in smc_release().

Reported-by: syzbot+0bf2e01269f1274b4b03@syzkaller.appspotmail.com
Reported-by: syzbot+e3132895630f957306bc@syzkaller.appspotmail.com
Signed-off-by: default avatarMyungho Jung <mhjungk@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f7db2beb
...@@ -147,8 +147,14 @@ static int smc_release(struct socket *sock) ...@@ -147,8 +147,14 @@ static int smc_release(struct socket *sock)
sk->sk_shutdown |= SHUTDOWN_MASK; sk->sk_shutdown |= SHUTDOWN_MASK;
} }
if (smc->clcsock) { if (smc->clcsock) {
if (smc->use_fallback && sk->sk_state == SMC_LISTEN) {
/* wake up clcsock accept */
rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR);
}
mutex_lock(&smc->clcsock_release_lock);
sock_release(smc->clcsock); sock_release(smc->clcsock);
smc->clcsock = NULL; smc->clcsock = NULL;
mutex_unlock(&smc->clcsock_release_lock);
} }
if (smc->use_fallback) { if (smc->use_fallback) {
if (sk->sk_state != SMC_LISTEN && sk->sk_state != SMC_INIT) if (sk->sk_state != SMC_LISTEN && sk->sk_state != SMC_INIT)
...@@ -205,6 +211,7 @@ static struct sock *smc_sock_alloc(struct net *net, struct socket *sock, ...@@ -205,6 +211,7 @@ static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
spin_lock_init(&smc->conn.send_lock); spin_lock_init(&smc->conn.send_lock);
sk->sk_prot->hash(sk); sk->sk_prot->hash(sk);
sk_refcnt_debug_inc(sk); sk_refcnt_debug_inc(sk);
mutex_init(&smc->clcsock_release_lock);
return sk; return sk;
} }
...@@ -821,7 +828,7 @@ static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc) ...@@ -821,7 +828,7 @@ static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
struct socket *new_clcsock = NULL; struct socket *new_clcsock = NULL;
struct sock *lsk = &lsmc->sk; struct sock *lsk = &lsmc->sk;
struct sock *new_sk; struct sock *new_sk;
int rc; int rc = -EINVAL;
release_sock(lsk); release_sock(lsk);
new_sk = smc_sock_alloc(sock_net(lsk), NULL, lsk->sk_protocol); new_sk = smc_sock_alloc(sock_net(lsk), NULL, lsk->sk_protocol);
...@@ -834,7 +841,10 @@ static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc) ...@@ -834,7 +841,10 @@ static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
} }
*new_smc = smc_sk(new_sk); *new_smc = smc_sk(new_sk);
mutex_lock(&lsmc->clcsock_release_lock);
if (lsmc->clcsock)
rc = kernel_accept(lsmc->clcsock, &new_clcsock, 0); rc = kernel_accept(lsmc->clcsock, &new_clcsock, 0);
mutex_unlock(&lsmc->clcsock_release_lock);
lock_sock(lsk); lock_sock(lsk);
if (rc < 0) if (rc < 0)
lsk->sk_err = -rc; lsk->sk_err = -rc;
......
...@@ -219,6 +219,10 @@ struct smc_sock { /* smc sock container */ ...@@ -219,6 +219,10 @@ struct smc_sock { /* smc sock container */
* started, waiting for unsent * started, waiting for unsent
* data to be sent * data to be sent
*/ */
struct mutex clcsock_release_lock;
/* protects clcsock of a listen
* socket
* */
}; };
static inline struct smc_sock *smc_sk(const struct sock *sk) static inline struct smc_sock *smc_sk(const struct sock *sk)
......
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