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can: bcm/raw/isotp: use per module netdevice notifier

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commit 8d0caedb759683041d9db82069937525999ada53 upstream.

syzbot is reporting hung task at register_netdevice_notifier() [1] and
unregister_netdevice_notifier() [2], for cleanup_net() might perform
time consuming operations while CAN driver's raw/bcm/isotp modules are
calling {register,unregister}_netdevice_notifier() on each socket.

Change raw/bcm/isotp modules to call register_netdevice_notifier() from
module's __init function and call unregister_netdevice_notifier() from
module's __exit function, as with gw/j1939 modules are doing.

Link: https://syzkaller.appspot.com/bug?id=391b9498827788b3cc6830226d4ff5be87107c30 [1]
Link: https://syzkaller.appspot.com/bug?id=1724d278c83ca6e6df100a2e320c10d991cf2bce [2]
Link: https://lore.kernel.org/r/54a5f451-05ed-f977-8534-79e7aa2bcc8f@i-love.sakura.ne.jp
Cc: linux-stable <stable@vger.kernel.org>
Reported-by: syzbot <syzbot+355f8edb2ff45d5f95fa@syzkaller.appspotmail.com>
Reported-by: syzbot <syzbot+0f1827363a305f74996f@syzkaller.appspotmail.com>
Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Tested-by: syzbot <syzbot+355f8edb2ff45d5f95fa@syzkaller.appspotmail.com>
Tested-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Tetsuo Handa 2021-06-05 19:26:35 +09:00 committed by Greg Kroah-Hartman
parent c297559a2a
commit 776e0d16ac
2 changed files with 94 additions and 27 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

59
net/can/bcm.c
View File

@ -127,7 +127,7 @@ struct bcm_sock {
struct sock sk;
int bound;
int ifindex;
struct notifier_block notifier;
struct list_head notifier;
struct list_head rx_ops;
struct list_head tx_ops;
unsigned long dropped_usr_msgs;
@ -135,6 +135,10 @@ struct bcm_sock {
char procname [32]; /* inode number in decimal with \0 */
};
static LIST_HEAD(bcm_notifier_list);
static DEFINE_SPINLOCK(bcm_notifier_lock);
static struct bcm_sock *bcm_busy_notifier;
static inline struct bcm_sock *bcm_sk(const struct sock *sk)
{
return (struct bcm_sock *)sk;
@ -1383,20 +1387,15 @@ static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
/*
* notification handler for netdevice status changes
*/
static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
void *ptr)
static void bcm_notify(struct bcm_sock *bo, unsigned long msg,
struct net_device *dev)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
struct bcm_sock *bo = container_of(nb, struct bcm_sock, notifier);
struct sock *sk = &bo->sk;
struct bcm_op *op;
int notify_enodev = 0;
if (!net_eq(dev_net(dev), sock_net(sk)))
return NOTIFY_DONE;
if (dev->type != ARPHRD_CAN)
return NOTIFY_DONE;
return;
switch (msg) {
@ -1431,7 +1430,28 @@ static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
sk->sk_error_report(sk);
}
}
}
static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
if (dev->type != ARPHRD_CAN)
return NOTIFY_DONE;
if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
return NOTIFY_DONE;
if (unlikely(bcm_busy_notifier)) /* Check for reentrant bug. */
return NOTIFY_DONE;
spin_lock(&bcm_notifier_lock);
list_for_each_entry(bcm_busy_notifier, &bcm_notifier_list, notifier) {
spin_unlock(&bcm_notifier_lock);
bcm_notify(bcm_busy_notifier, msg, dev);
spin_lock(&bcm_notifier_lock);
}
bcm_busy_notifier = NULL;
spin_unlock(&bcm_notifier_lock);
return NOTIFY_DONE;
}
@ -1451,9 +1471,9 @@ static int bcm_init(struct sock *sk)
INIT_LIST_HEAD(&bo->rx_ops);
/* set notifier */
bo->notifier.notifier_call = bcm_notifier;
register_netdevice_notifier(&bo->notifier);
spin_lock(&bcm_notifier_lock);
list_add_tail(&bo->notifier, &bcm_notifier_list);
spin_unlock(&bcm_notifier_lock);
return 0;
}
@ -1476,7 +1496,14 @@ static int bcm_release(struct socket *sock)
/* remove bcm_ops, timer, rx_unregister(), etc. */
unregister_netdevice_notifier(&bo->notifier);
spin_lock(&bcm_notifier_lock);
while (bcm_busy_notifier == bo) {
spin_unlock(&bcm_notifier_lock);
schedule_timeout_uninterruptible(1);
spin_lock(&bcm_notifier_lock);
}
list_del(&bo->notifier);
spin_unlock(&bcm_notifier_lock);
lock_sock(sk);
@ -1699,6 +1726,10 @@ static struct pernet_operations canbcm_pernet_ops __read_mostly = {
.exit = canbcm_pernet_exit,
};
static struct notifier_block canbcm_notifier = {
.notifier_call = bcm_notifier
};
static int __init bcm_module_init(void)
{
int err;
@ -1712,12 +1743,14 @@ static int __init bcm_module_init(void)
}
register_pernet_subsys(&canbcm_pernet_ops);
register_netdevice_notifier(&canbcm_notifier);
return 0;
}
static void __exit bcm_module_exit(void)
{
can_proto_unregister(&bcm_can_proto);
unregister_netdevice_notifier(&canbcm_notifier);
unregister_pernet_subsys(&canbcm_pernet_ops);
}

62
net/can/raw.c
View File

@ -85,7 +85,7 @@ struct raw_sock {
struct sock sk;
int bound;
int ifindex;
struct notifier_block notifier;
struct list_head notifier;
int loopback;
int recv_own_msgs;
int fd_frames;
@ -97,6 +97,10 @@ struct raw_sock {
struct uniqframe __percpu *uniq;
};
static LIST_HEAD(raw_notifier_list);
static DEFINE_SPINLOCK(raw_notifier_lock);
static struct raw_sock *raw_busy_notifier;
/* Return pointer to store the extra msg flags for raw_recvmsg().
* We use the space of one unsigned int beyond the 'struct sockaddr_can'
* in skb->cb.
@ -265,21 +269,16 @@ static int raw_enable_allfilters(struct net *net, struct net_device *dev,
return err;
}
static int raw_notifier(struct notifier_block *nb,
unsigned long msg, void *ptr)
static void raw_notify(struct raw_sock *ro, unsigned long msg,
struct net_device *dev)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
struct raw_sock *ro = container_of(nb, struct raw_sock, notifier);
struct sock *sk = &ro->sk;
if (!net_eq(dev_net(dev), sock_net(sk)))
return NOTIFY_DONE;
if (dev->type != ARPHRD_CAN)
return NOTIFY_DONE;
return;
if (ro->ifindex != dev->ifindex)
return NOTIFY_DONE;
return;
switch (msg) {
case NETDEV_UNREGISTER:
@ -307,7 +306,28 @@ static int raw_notifier(struct notifier_block *nb,
sk->sk_error_report(sk);
break;
}
}
static int raw_notifier(struct notifier_block *nb, unsigned long msg,
void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
if (dev->type != ARPHRD_CAN)
return NOTIFY_DONE;
if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
return NOTIFY_DONE;
if (unlikely(raw_busy_notifier)) /* Check for reentrant bug. */
return NOTIFY_DONE;
spin_lock(&raw_notifier_lock);
list_for_each_entry(raw_busy_notifier, &raw_notifier_list, notifier) {
spin_unlock(&raw_notifier_lock);
raw_notify(raw_busy_notifier, msg, dev);
spin_lock(&raw_notifier_lock);
}
raw_busy_notifier = NULL;
spin_unlock(&raw_notifier_lock);
return NOTIFY_DONE;
}
@ -336,9 +356,9 @@ static int raw_init(struct sock *sk)
return -ENOMEM;
/* set notifier */
ro->notifier.notifier_call = raw_notifier;
register_netdevice_notifier(&ro->notifier);
spin_lock(&raw_notifier_lock);
list_add_tail(&ro->notifier, &raw_notifier_list);
spin_unlock(&raw_notifier_lock);
return 0;
}
@ -353,7 +373,14 @@ static int raw_release(struct socket *sock)
ro = raw_sk(sk);
unregister_netdevice_notifier(&ro->notifier);
spin_lock(&raw_notifier_lock);
while (raw_busy_notifier == ro) {
spin_unlock(&raw_notifier_lock);
schedule_timeout_uninterruptible(1);
spin_lock(&raw_notifier_lock);
}
list_del(&ro->notifier);
spin_unlock(&raw_notifier_lock);
lock_sock(sk);
@ -879,6 +906,10 @@ static const struct can_proto raw_can_proto = {
.prot = &raw_proto,
};
static struct notifier_block canraw_notifier = {
.notifier_call = raw_notifier
};
static __init int raw_module_init(void)
{
int err;
@ -888,6 +919,8 @@ static __init int raw_module_init(void)
err = can_proto_register(&raw_can_proto);
if (err < 0)
pr_err("can: registration of raw protocol failed\n");
else
register_netdevice_notifier(&canraw_notifier);
return err;
}
@ -895,6 +928,7 @@ static __init int raw_module_init(void)
static __exit void raw_module_exit(void)
{
can_proto_unregister(&raw_can_proto);
unregister_netdevice_notifier(&canraw_notifier);
}
module_init(raw_module_init);