From: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
[ Upstream commit 5aa2820177af650293b2f9f1873c1f6f8e4ad7a4 ]
hsr_forward_skb() a skb and keeps information in an on-stack
hsr_frame_info. hsr_get_node() assigns hsr_frame_info::node_src which is
from a RCU list. This pointer is used later in hsr_forward_do().
I don't see a reason why this pointer can't vanish midway since there is
no guarantee that hsr_forward_skb() is invoked from an RCU read section.
Use rcu_read_lock() to protect hsr_frame_info::node_src from its
assignment until it is no longer used.
Fixes: f266a683a4804 ("net/hsr: Better frame dispatch")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/hsr/hsr_forward.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/net/hsr/hsr_forward.c b/net/hsr/hsr_forward.c
index 07892c4b6d0c..daf6abbadeb9 100644
--- a/net/hsr/hsr_forward.c
+++ b/net/hsr/hsr_forward.c
@@ -572,11 +572,13 @@ void hsr_forward_skb(struct sk_buff *skb, struct hsr_port *port)
{
struct hsr_frame_info frame;
+ rcu_read_lock();
if (fill_frame_info(&frame, skb, port) < 0)
goto out_drop;
hsr_register_frame_in(frame.node_src, port, frame.sequence_nr);
hsr_forward_do(&frame);
+ rcu_read_unlock();
/* Gets called for ingress frames as well as egress from master port.
* So check and increment stats for master port only here.
*/
@@ -591,6 +593,7 @@ void hsr_forward_skb(struct sk_buff *skb, struct hsr_port *port)
return;
out_drop:
+ rcu_read_unlock();
port->dev->stats.tx_dropped++;
kfree_skb(skb);
}
--
2.35.1
