From bb8872a1e6bc911869a729240781076ed950764b Mon Sep 17 00:00:00 2001 From: Tuong Lien Date: Sun, 30 Aug 2020 02:37:55 +0700 Subject: tipc: fix using smp_processor_id() in preemptible The 'this_cpu_ptr()' is used to obtain the AEAD key' TFM on the current CPU for encryption, however the execution can be preemptible since it's actually user-space context, so the 'using smp_processor_id() in preemptible' has been observed. We fix the issue by using the 'get/put_cpu_ptr()' API which consists of a 'preempt_disable()' instead. Fixes: fc1b6d6de220 ("tipc: introduce TIPC encryption & authentication") Acked-by: Jon Maloy Signed-off-by: Tuong Lien Signed-off-by: David S. Miller --- net/tipc/crypto.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) (limited to 'net/tipc') diff --git a/net/tipc/crypto.c b/net/tipc/crypto.c index c38babaa4e57..7c523dc81575 100644 --- a/net/tipc/crypto.c +++ b/net/tipc/crypto.c @@ -326,7 +326,8 @@ static void tipc_aead_free(struct rcu_head *rp) if (aead->cloned) { tipc_aead_put(aead->cloned); } else { - head = *this_cpu_ptr(aead->tfm_entry); + head = *get_cpu_ptr(aead->tfm_entry); + put_cpu_ptr(aead->tfm_entry); list_for_each_entry_safe(tfm_entry, tmp, &head->list, list) { crypto_free_aead(tfm_entry->tfm); list_del(&tfm_entry->list); @@ -399,10 +400,15 @@ static void tipc_aead_users_set(struct tipc_aead __rcu *aead, int val) */ static struct crypto_aead *tipc_aead_tfm_next(struct tipc_aead *aead) { - struct tipc_tfm **tfm_entry = this_cpu_ptr(aead->tfm_entry); + struct tipc_tfm **tfm_entry; + struct crypto_aead *tfm; + tfm_entry = get_cpu_ptr(aead->tfm_entry); *tfm_entry = list_next_entry(*tfm_entry, list); - return (*tfm_entry)->tfm; + tfm = (*tfm_entry)->tfm; + put_cpu_ptr(tfm_entry); + + return tfm; } /** -- cgit v1.2.3-58-ga151 From 2a63866c8b51a3f72cea388dfac259d0e14c4ba6 Mon Sep 17 00:00:00 2001 From: Tetsuo Handa Date: Wed, 2 Sep 2020 22:44:16 +0900 Subject: tipc: fix shutdown() of connectionless socket syzbot is reporting hung task at nbd_ioctl() [1], for there are two problems regarding TIPC's connectionless socket's shutdown() operation. ---------- #include #include #include #include #include int main(int argc, char *argv[]) { const int fd = open("/dev/nbd0", 3); alarm(5); ioctl(fd, NBD_SET_SOCK, socket(PF_TIPC, SOCK_DGRAM, 0)); ioctl(fd, NBD_DO_IT, 0); /* To be interrupted by SIGALRM. */ return 0; } ---------- One problem is that wait_for_completion() from flush_workqueue() from nbd_start_device_ioctl() from nbd_ioctl() cannot be completed when nbd_start_device_ioctl() received a signal at wait_event_interruptible(), for tipc_shutdown() from kernel_sock_shutdown(SHUT_RDWR) from nbd_mark_nsock_dead() from sock_shutdown() from nbd_start_device_ioctl() is failing to wake up a WQ thread sleeping at wait_woken() from tipc_wait_for_rcvmsg() from sock_recvmsg() from sock_xmit() from nbd_read_stat() from recv_work() scheduled by nbd_start_device() from nbd_start_device_ioctl(). Fix this problem by always invoking sk->sk_state_change() (like inet_shutdown() does) when tipc_shutdown() is called. The other problem is that tipc_wait_for_rcvmsg() cannot return when tipc_shutdown() is called, for tipc_shutdown() sets sk->sk_shutdown to SEND_SHUTDOWN (despite "how" is SHUT_RDWR) while tipc_wait_for_rcvmsg() needs sk->sk_shutdown set to RCV_SHUTDOWN or SHUTDOWN_MASK. Fix this problem by setting sk->sk_shutdown to SHUTDOWN_MASK (like inet_shutdown() does) when the socket is connectionless. [1] https://syzkaller.appspot.com/bug?id=3fe51d307c1f0a845485cf1798aa059d12bf18b2 Reported-by: syzbot Signed-off-by: Tetsuo Handa Signed-off-by: David S. Miller --- net/tipc/socket.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'net/tipc') diff --git a/net/tipc/socket.c b/net/tipc/socket.c index 07419f36116a..d49c6173954a 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -2771,18 +2771,21 @@ static int tipc_shutdown(struct socket *sock, int how) trace_tipc_sk_shutdown(sk, NULL, TIPC_DUMP_ALL, " "); __tipc_shutdown(sock, TIPC_CONN_SHUTDOWN); - sk->sk_shutdown = SEND_SHUTDOWN; + if (tipc_sk_type_connectionless(sk)) + sk->sk_shutdown = SHUTDOWN_MASK; + else + sk->sk_shutdown = SEND_SHUTDOWN; if (sk->sk_state == TIPC_DISCONNECTING) { /* Discard any unreceived messages */ __skb_queue_purge(&sk->sk_receive_queue); - /* Wake up anyone sleeping in poll */ - sk->sk_state_change(sk); res = 0; } else { res = -ENOTCONN; } + /* Wake up anyone sleeping in poll. */ + sk->sk_state_change(sk); release_sock(sk); return res; -- cgit v1.2.3-58-ga151