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can: raw: fix receiver memory leak

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[ Upstream commit ee8b94c851 ]

Got kmemleak errors with the following ltp can_filter testcase:

for ((i=1; i<=100; i++))
do
        ./can_filter &
        sleep 0.1
done

==============================================================
[<00000000db4a4943>] can_rx_register+0x147/0x360 [can]
[<00000000a289549d>] raw_setsockopt+0x5ef/0x853 [can_raw]
[<000000006d3d9ebd>] __sys_setsockopt+0x173/0x2c0
[<00000000407dbfec>] __x64_sys_setsockopt+0x61/0x70
[<00000000fd468496>] do_syscall_64+0x33/0x40
[<00000000b7e47d51>] entry_SYSCALL_64_after_hwframe+0x61/0xc6

It's a bug in the concurrent scenario of unregister_netdevice_many()
and raw_release() as following:

             cpu0                                        cpu1
unregister_netdevice_many(can_dev)
  unlist_netdevice(can_dev) // dev_get_by_index() return NULL after this
  net_set_todo(can_dev)
						raw_release(can_socket)
						  dev = dev_get_by_index(, ro->ifindex); // dev == NULL
						  if (dev) { // receivers in dev_rcv_lists not free because dev is NULL
						    raw_disable_allfilters(, dev, );
						    dev_put(dev);
						  }
						  ...
						  ro->bound = 0;
						  ...

call_netdevice_notifiers(NETDEV_UNREGISTER, )
  raw_notify(, NETDEV_UNREGISTER, )
    if (ro->bound) // invalid because ro->bound has been set 0
      raw_disable_allfilters(, dev, ); // receivers in dev_rcv_lists will never be freed

Add a net_device pointer member in struct raw_sock to record bound
can_dev, and use rtnl_lock to serialize raw_socket members between
raw_bind(), raw_release(), raw_setsockopt() and raw_notify(). Use
ro->dev to decide whether to free receivers in dev_rcv_lists.

Fixes: 8d0caedb75 ("can: bcm/raw/isotp: use per module netdevice notifier")
Reviewed-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Link: https://lore.kernel.org/all/20230711011737.1969582-1-william.xuanziyang@huawei.com
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Ziyang Xuan 2023-07-11 09:17:37 +08:00 • committed by Justin Hammond
parent 1fdbd5ddf3
commit 9411a38299
1 changed files with 24 additions and 33 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

57
net/can/raw.c
View file

@ -83,6 +83,7 @@ struct raw_sock {
struct sock sk;
int bound;
int ifindex;
struct net_device *dev;
struct list_head notifier;
int loopback;
int recv_own_msgs;
@ -275,7 +276,7 @@ static void raw_notify(struct raw_sock *ro, unsigned long msg,
if (!net_eq(dev_net(dev), sock_net(sk)))
return;
if (ro->ifindex != dev->ifindex)
if (ro->dev != dev)
return;
switch (msg) {
@ -290,6 +291,7 @@ static void raw_notify(struct raw_sock *ro, unsigned long msg,
ro->ifindex = 0;
ro->bound = 0;
ro->dev = NULL;
ro->count = 0;
release_sock(sk);
@ -335,6 +337,7 @@ static int raw_init(struct sock *sk)
ro->bound = 0;
ro->ifindex = 0;
ro->dev = NULL;
/* set default filter to single entry dfilter */
ro->dfilter.can_id = 0;
@ -382,19 +385,13 @@ static int raw_release(struct socket *sock)
lock_sock(sk);
rtnl_lock();
/* remove current filters & unregister */
if (ro->bound) {
if (ro->ifindex) {
struct net_device *dev;
dev = dev_get_by_index(sock_net(sk), ro->ifindex);
if (dev) {
raw_disable_allfilters(dev_net(dev), dev, sk);
dev_put(dev);
}
} else {
if (ro->dev)
raw_disable_allfilters(dev_net(ro->dev), ro->dev, sk);
else
raw_disable_allfilters(sock_net(sk), NULL, sk);
}
}
if (ro->count > 1)
@ -402,8 +399,10 @@ static int raw_release(struct socket *sock)
ro->ifindex = 0;
ro->bound = 0;
ro->dev = NULL;
ro->count = 0;
free_percpu(ro->uniq);
rtnl_unlock();
sock_orphan(sk);
sock->sk = NULL;
@ -419,6 +418,7 @@ static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len)
struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
struct sock *sk = sock->sk;
struct raw_sock *ro = raw_sk(sk);
struct net_device *dev = NULL;
int ifindex;
int err = 0;
int notify_enetdown = 0;
@ -428,14 +428,13 @@ static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len)
if (addr->can_family != AF_CAN)
return -EINVAL;
rtnl_lock();
lock_sock(sk);
if (ro->bound && addr->can_ifindex == ro->ifindex)
goto out;
if (addr->can_ifindex) {
struct net_device *dev;
dev = dev_get_by_index(sock_net(sk), addr->can_ifindex);
if (!dev) {
err = -ENODEV;
@ -464,26 +463,20 @@ static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len)
if (!err) {
if (ro->bound) {
/* unregister old filters */
if (ro->ifindex) {
struct net_device *dev;
dev = dev_get_by_index(sock_net(sk),
ro->ifindex);
if (dev) {
raw_disable_allfilters(dev_net(dev),
dev, sk);
dev_put(dev);
}
} else {
if (ro->dev)
raw_disable_allfilters(dev_net(ro->dev),
ro->dev, sk);
else
raw_disable_allfilters(sock_net(sk), NULL, sk);
}
}
ro->ifindex = ifindex;
ro->bound = 1;
ro->dev = dev;
}
out:
release_sock(sk);
rtnl_unlock();
if (notify_enetdown) {
sk->sk_err = ENETDOWN;
@ -549,9 +542,9 @@ static int raw_setsockopt(struct socket *sock, int level, int optname,
rtnl_lock();
lock_sock(sk);
if (ro->bound && ro->ifindex) {
dev = dev_get_by_index(sock_net(sk), ro->ifindex);
if (!dev) {
dev = ro->dev;
if (ro->bound && dev) {
if (dev->reg_state != NETREG_REGISTERED) {
if (count > 1)
kfree(filter);
err = -ENODEV;
@ -592,7 +585,6 @@ static int raw_setsockopt(struct socket *sock, int level, int optname,
ro->count = count;
out_fil:
dev_put(dev);
release_sock(sk);
rtnl_unlock();
@ -610,9 +602,9 @@ static int raw_setsockopt(struct socket *sock, int level, int optname,
rtnl_lock();
lock_sock(sk);
if (ro->bound && ro->ifindex) {
dev = dev_get_by_index(sock_net(sk), ro->ifindex);
if (!dev) {
dev = ro->dev;
if (ro->bound && dev) {
if (dev->reg_state != NETREG_REGISTERED) {
err = -ENODEV;
goto out_err;
}
@ -636,7 +628,6 @@ static int raw_setsockopt(struct socket *sock, int level, int optname,
ro->err_mask = err_mask;
out_err:
dev_put(dev);
release_sock(sk);
rtnl_unlock();