diff options
Diffstat (limited to 'net/can')
| -rw-r--r-- | net/can/isotp.c | 29 |
1 files changed, 22 insertions, 7 deletions
diff --git a/net/can/isotp.c b/net/can/isotp.c index 02cbcb2ecf0d..d2a430b6a13b 100644 --- a/net/can/isotp.c +++ b/net/can/isotp.c @@ -56,6 +56,7 @@ #include <linux/module.h> #include <linux/init.h> #include <linux/interrupt.h> +#include <linux/spinlock.h> #include <linux/hrtimer.h> #include <linux/wait.h> #include <linux/uio.h> @@ -145,6 +146,7 @@ struct isotp_sock { struct tpcon rx, tx; struct list_head notifier; wait_queue_head_t wait; + spinlock_t rx_lock; /* protect single thread state machine */ }; static LIST_HEAD(isotp_notifier_list); @@ -615,11 +617,17 @@ static void isotp_rcv(struct sk_buff *skb, void *data) n_pci_type = cf->data[ae] & 0xF0; + /* Make sure the state changes and data structures stay consistent at + * CAN frame reception time. This locking is not needed in real world + * use cases but the inconsistency can be triggered with syzkaller. + */ + spin_lock(&so->rx_lock); + if (so->opt.flags & CAN_ISOTP_HALF_DUPLEX) { /* check rx/tx path half duplex expectations */ if ((so->tx.state != ISOTP_IDLE && n_pci_type != N_PCI_FC) || (so->rx.state != ISOTP_IDLE && n_pci_type == N_PCI_FC)) - return; + goto out_unlock; } switch (n_pci_type) { @@ -668,6 +676,9 @@ static void isotp_rcv(struct sk_buff *skb, void *data) isotp_rcv_cf(sk, cf, ae, skb); break; } + +out_unlock: + spin_unlock(&so->rx_lock); } static void isotp_fill_dataframe(struct canfd_frame *cf, struct isotp_sock *so, @@ -876,7 +887,7 @@ static int isotp_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) if (!size || size > MAX_MSG_LENGTH) { err = -EINVAL; - goto err_out; + goto err_out_drop; } /* take care of a potential SF_DL ESC offset for TX_DL > 8 */ @@ -886,24 +897,24 @@ static int isotp_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) if ((so->opt.flags & CAN_ISOTP_SF_BROADCAST) && (size > so->tx.ll_dl - SF_PCI_SZ4 - ae - off)) { err = -EINVAL; - goto err_out; + goto err_out_drop; } err = memcpy_from_msg(so->tx.buf, msg, size); if (err < 0) - goto err_out; + goto err_out_drop; dev = dev_get_by_index(sock_net(sk), so->ifindex); if (!dev) { err = -ENXIO; - goto err_out; + goto err_out_drop; } skb = sock_alloc_send_skb(sk, so->ll.mtu + sizeof(struct can_skb_priv), msg->msg_flags & MSG_DONTWAIT, &err); if (!skb) { dev_put(dev); - goto err_out; + goto err_out_drop; } can_skb_reserve(skb); @@ -965,7 +976,7 @@ static int isotp_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) if (err) { pr_notice_once("can-isotp: %s: can_send_ret %pe\n", __func__, ERR_PTR(err)); - goto err_out; + goto err_out_drop; } if (wait_tx_done) { @@ -978,6 +989,9 @@ static int isotp_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) return size; +err_out_drop: + /* drop this PDU and unlock a potential wait queue */ + old_state = ISOTP_IDLE; err_out: so->tx.state = old_state; if (so->tx.state == ISOTP_IDLE) @@ -1444,6 +1458,7 @@ static int isotp_init(struct sock *sk) so->txtimer.function = isotp_tx_timer_handler; init_waitqueue_head(&so->wait); + spin_lock_init(&so->rx_lock); spin_lock(&isotp_notifier_lock); list_add_tail(&so->notifier, &isotp_notifier_list); |