6.12-stable review patch. If anyone has any objections, please let me know.
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From: Hangbin Liu liuhangbin@gmail.com
[ Upstream commit 847748fc66d08a89135a74e29362a66ba4e3ab15 ]
hsr_get_port_ndev calls hsr_for_each_port, which need to hold rcu lock. On the other hand, before return the port device, we need to hold the device reference to avoid UaF in the caller function.
Suggested-by: Paolo Abeni pabeni@redhat.com Fixes: 9c10dd8eed74 ("net: hsr: Create and export hsr_get_port_ndev()") Signed-off-by: Hangbin Liu liuhangbin@gmail.com Reviewed-by: Simon Horman horms@kernel.org Link: https://patch.msgid.link/20250905091533.377443-4-liuhangbin@gmail.com Signed-off-by: Paolo Abeni pabeni@redhat.com [ Drop multicast filtering changes ] Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/hsr/hsr_device.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
--- a/net/hsr/hsr_device.c +++ b/net/hsr/hsr_device.c @@ -682,9 +682,14 @@ struct net_device *hsr_get_port_ndev(str struct hsr_priv *hsr = netdev_priv(ndev); struct hsr_port *port;
+ rcu_read_lock(); hsr_for_each_port(hsr, port) - if (port->type == pt) + if (port->type == pt) { + dev_hold(port->dev); + rcu_read_unlock(); return port->dev; + } + rcu_read_unlock(); return NULL; } EXPORT_SYMBOL(hsr_get_port_ndev);