This is a note to let you know that I've just added the patch titled
can: j1939: change j1939_netdev_lock type to mutex
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
can-j1939-change-j1939_netdev_lock-type-to-mutex.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From cd9c790de2088b0d797dc4d244b4f174f9962554 Mon Sep 17 00:00:00 2001
From: Fedor Pchelkin <pchelkin@xxxxxxxxx>
Date: Fri, 26 May 2023 20:19:09 +0300
Subject: can: j1939: change j1939_netdev_lock type to mutex
From: Fedor Pchelkin <pchelkin@xxxxxxxxx>
commit cd9c790de2088b0d797dc4d244b4f174f9962554 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/can/j1939/main.c | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)
--- a/net/can/j1939/main.c
+++ b/net/can/j1939/main.c
@@ -122,7 +122,7 @@ static void j1939_can_recv(struct sk_buf
#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)
{
@@ -216,7 +216,7 @@ static void __j1939_rx_release(struct kr
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 */
@@ -244,9 +244,9 @@ static struct j1939_priv *j1939_priv_get
{
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;
}
@@ -256,14 +256,14 @@ struct j1939_priv *j1939_netdev_start(st
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)
@@ -273,20 +273,20 @@ struct j1939_priv *j1939_netdev_start(st
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)
@@ -304,7 +304,7 @@ struct j1939_priv *j1939_netdev_start(st
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);
}
Patches currently in stable-queue which might be from pchelkin@xxxxxxxxx are
queue-5.4/can-j1939-change-j1939_netdev_lock-type-to-mutex.patch
queue-5.4/can-j1939-avoid-possible-use-after-free-when-j1939_can_rx_register-fails.patch
