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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 acb755be1f
commit 0cf4b37790
3 changed files with 142 additions and 40 deletions
Download Patch File Download Diff File Expand all files Collapse all files

59
net/can/bcm.c
View File

@@ -125,7 +125,7 @@ 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;
@@ -133,6 +133,10 @@ 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;
@@ -1381,20 +1385,15 @@ 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) {
@@ -1429,7 +1428,28 @@ 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;
}
@@ -1449,9 +1469,9 @@ 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;
}
@@ -1474,7 +1494,14 @@ 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);
@@ -1695,6 +1722,10 @@ 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;
@@ -1708,12 +1739,14 @@ 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);
}