From: Fedor Pchelkin <pchelkin@xxxxxxxxx>
It turns out access to j1939_can_rx_register() needs to be serialized,
otherwise j1939_priv can be corrupted when parallel threads call
j1939_netdev_start() and j1939_can_rx_register() fails. This issue is
thoroughly covered in other commit which serializes access to
j1939_can_rx_register().
Change j1939_netdev_lock type to mutex so that we do not need to remove
GFP_KERNEL from can_rx_register().
j1939_netdev_lock seems to be used in normal contexts where mutex usage
is not prohibited.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Suggested-by: Alexey Khoroshilov <khoroshilov@xxxxxxxxx>
Signed-off-by: Fedor Pchelkin <pchelkin@xxxxxxxxx>
Tested-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
Acked-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230526171910.227615-2-pchelkin@xxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
---
net/can/j1939/main.c | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)
diff --git a/net/can/j1939/main.c b/net/can/j1939/main.c
index 821d4ff303b3..6ed79afe19a5 100644
--- a/net/can/j1939/main.c
+++ b/net/can/j1939/main.c
@@ -126,7 +126,7 @@ static void j1939_can_recv(struct sk_buff *iskb, void *data)
#define J1939_CAN_ID CAN_EFF_FLAG
#define J1939_CAN_MASK (CAN_EFF_FLAG | CAN_RTR_FLAG)
-static DEFINE_SPINLOCK(j1939_netdev_lock);
+static DEFINE_MUTEX(j1939_netdev_lock);
static struct j1939_priv *j1939_priv_create(struct net_device *ndev)
{
@@ -220,7 +220,7 @@ static void __j1939_rx_release(struct kref *kref)
j1939_can_rx_unregister(priv);
j1939_ecu_unmap_all(priv);
j1939_priv_set(priv->ndev, NULL);
- spin_unlock(&j1939_netdev_lock);
+ mutex_unlock(&j1939_netdev_lock);
}
/* get pointer to priv without increasing ref counter */
@@ -248,9 +248,9 @@ static struct j1939_priv *j1939_priv_get_by_ndev(struct net_device *ndev)
{
struct j1939_priv *priv;
- spin_lock(&j1939_netdev_lock);
+ mutex_lock(&j1939_netdev_lock);
priv = j1939_priv_get_by_ndev_locked(ndev);
- spin_unlock(&j1939_netdev_lock);
+ mutex_unlock(&j1939_netdev_lock);
return priv;
}
@@ -260,14 +260,14 @@ struct j1939_priv *j1939_netdev_start(struct net_device *ndev)
struct j1939_priv *priv, *priv_new;
int ret;
- spin_lock(&j1939_netdev_lock);
+ mutex_lock(&j1939_netdev_lock);
priv = j1939_priv_get_by_ndev_locked(ndev);
if (priv) {
kref_get(&priv->rx_kref);
- spin_unlock(&j1939_netdev_lock);
+ mutex_unlock(&j1939_netdev_lock);
return priv;
}
- spin_unlock(&j1939_netdev_lock);
+ mutex_unlock(&j1939_netdev_lock);
priv = j1939_priv_create(ndev);
if (!priv)
@@ -277,20 +277,20 @@ struct j1939_priv *j1939_netdev_start(struct net_device *ndev)
spin_lock_init(&priv->j1939_socks_lock);
INIT_LIST_HEAD(&priv->j1939_socks);
- spin_lock(&j1939_netdev_lock);
+ mutex_lock(&j1939_netdev_lock);
priv_new = j1939_priv_get_by_ndev_locked(ndev);
if (priv_new) {
/* Someone was faster than us, use their priv and roll
* back our's.
*/
kref_get(&priv_new->rx_kref);
- spin_unlock(&j1939_netdev_lock);
+ mutex_unlock(&j1939_netdev_lock);
dev_put(ndev);
kfree(priv);
return priv_new;
}
j1939_priv_set(ndev, priv);
- spin_unlock(&j1939_netdev_lock);
+ mutex_unlock(&j1939_netdev_lock);
ret = j1939_can_rx_register(priv);
if (ret < 0)
@@ -308,7 +308,7 @@ struct j1939_priv *j1939_netdev_start(struct net_device *ndev)
void j1939_netdev_stop(struct j1939_priv *priv)
{
- kref_put_lock(&priv->rx_kref, __j1939_rx_release, &j1939_netdev_lock);
+ kref_put_mutex(&priv->rx_kref, __j1939_rx_release, &j1939_netdev_lock);
j1939_priv_put(priv);
}
--
2.39.2
