* [PATCH net] can: j1939: fix UAF for rx_kref of j1939_priv
@ 2021-09-26 10:47 Ziyang Xuan
2021-10-08 11:34 ` Oleksij Rempel
2021-10-17 10:43 ` Marc Kleine-Budde
0 siblings, 2 replies; 3+ messages in thread
From: Ziyang Xuan @ 2021-09-26 10:47 UTC (permalink / raw)
To: robin; +Cc: linux, socketcan, mkl, davem, kuba, linux-can, netdev, linux-kernel
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")
Reported-by: syzbot+85d9878b19c94f9019ad@syzkaller.appspotmail.com
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
---
net/can/j1939/main.c | 7 +++++--
1 file 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);
--
2.25.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH net] can: j1939: fix UAF for rx_kref of j1939_priv
2021-09-26 10:47 [PATCH net] can: j1939: fix UAF for rx_kref of j1939_priv Ziyang Xuan
@ 2021-10-08 11:34 ` Oleksij Rempel
2021-10-17 10:43 ` Marc Kleine-Budde
1 sibling, 0 replies; 3+ messages in thread
From: Oleksij Rempel @ 2021-10-08 11:34 UTC (permalink / raw)
To: Ziyang Xuan
Cc: robin, linux, socketcan, mkl, davem, kuba, linux-can, netdev,
linux-kernel
Hi,
On Sun, Sep 26, 2021 at 06:47:57PM +0800, Ziyang Xuan wrote:
> 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")
> Reported-by: syzbot+85d9878b19c94f9019ad@syzkaller.appspotmail.com
> Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Thank you!
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
> ---
> net/can/j1939/main.c | 7 +++++--
> 1 file 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);
> --
> 2.25.1
>
>
--
Pengutronix e.K. | |
Steuerwalder Str. 21 | http://www.pengutronix.de/ |
31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH net] can: j1939: fix UAF for rx_kref of j1939_priv
2021-09-26 10:47 [PATCH net] can: j1939: fix UAF for rx_kref of j1939_priv Ziyang Xuan
2021-10-08 11:34 ` Oleksij Rempel
@ 2021-10-17 10:43 ` Marc Kleine-Budde
1 sibling, 0 replies; 3+ messages in thread
From: Marc Kleine-Budde @ 2021-10-17 10:43 UTC (permalink / raw)
To: Ziyang Xuan
Cc: robin, linux, socketcan, davem, kuba, linux-can, netdev, linux-kernel
[-- Attachment #1: Type: text/plain, Size: 1684 bytes --]
On 26.09.2021 18:47:57, Ziyang Xuan wrote:
> 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")
> Reported-by: syzbot+85d9878b19c94f9019ad@syzkaller.appspotmail.com
> Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Added to linux-can/testing, added stable on Cc.
Thanks,
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Embedded Linux | https://www.pengutronix.de |
Vertretung West/Dortmund | Phone: +49-231-2826-924 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
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2021-09-26 10:47 [PATCH net] can: j1939: fix UAF for rx_kref of j1939_priv Ziyang Xuan
2021-10-08 11:34 ` Oleksij Rempel
2021-10-17 10:43 ` Marc Kleine-Budde
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