diff options
| author | Ziyang Xuan <william.xuanziyang@huawei.com> | 2021-09-26 18:47:57 +0800 |
|---|---|---|
| committer | Marc Kleine-Budde <mkl@pengutronix.de> | 2021-10-17 14:12:56 +0200 |
| commit | d9d52a3ebd284882f5562c88e55991add5d01586 (patch) | |
| tree | 7258e3bc16fb5a97bb63cf59910890500ad3cd29 /net/can | |
| parent | b504a884f6b5a77dac7d580ffa08e482f70d1a30 (diff) | |
can: j1939: j1939_netdev_start(): fix UAF for rx_kref of j1939_priv
It will trigger UAF for rx_kref of j1939_priv as following.
cpu0 cpu1
j1939_sk_bind(socket0, ndev0, ...)
j1939_netdev_start
j1939_sk_bind(socket1, ndev0, ...)
j1939_netdev_start
j1939_priv_set
j1939_priv_get_by_ndev_locked
j1939_jsk_add
.....
j1939_netdev_stop
kref_put_lock(&priv->rx_kref, ...)
kref_get(&priv->rx_kref, ...)
REFCOUNT_WARN("addition on 0;...")
====================================================
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 1 PID: 20874 at lib/refcount.c:25 refcount_warn_saturate+0x169/0x1e0
RIP: 0010:refcount_warn_saturate+0x169/0x1e0
Call Trace:
j1939_netdev_start+0x68b/0x920
j1939_sk_bind+0x426/0xeb0
? security_socket_bind+0x83/0xb0
The rx_kref's kref_get() and kref_put() should use j1939_netdev_lock to
protect.
Fixes: 9d71dd0c70099 ("can: add support of SAE J1939 protocol")
Link: https://lore.kernel.org/all/20210926104757.2021540-1-william.xuanziyang@huawei.com
Cc: stable@vger.kernel.org
Reported-by: syzbot+85d9878b19c94f9019ad@syzkaller.appspotmail.com
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'net/can')
| -rw-r--r-- | net/can/j1939/main.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/net/can/j1939/main.c b/net/can/j1939/main.c index 08c8606cfd9c..9bc55ecb37f9 100644 --- a/net/can/j1939/main.c +++ b/net/can/j1939/main.c @@ -249,11 +249,14 @@ struct j1939_priv *j1939_netdev_start(struct net_device *ndev) struct j1939_priv *priv, *priv_new; int ret; - priv = j1939_priv_get_by_ndev(ndev); + spin_lock(&j1939_netdev_lock); + priv = j1939_priv_get_by_ndev_locked(ndev); if (priv) { kref_get(&priv->rx_kref); + spin_unlock(&j1939_netdev_lock); return priv; } + spin_unlock(&j1939_netdev_lock); priv = j1939_priv_create(ndev); if (!priv) @@ -269,10 +272,10 @@ struct j1939_priv *j1939_netdev_start(struct net_device *ndev) /* Someone was faster than us, use their priv and roll * back our's. */ + kref_get(&priv_new->rx_kref); spin_unlock(&j1939_netdev_lock); dev_put(ndev); kfree(priv); - kref_get(&priv_new->rx_kref); return priv_new; } j1939_priv_set(ndev, priv); |