5.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Kaixin Wang <kxwang23@xxxxxxxxxxxxxx>
[ Upstream commit b5109b60ee4fcb2f2bb24f589575e10cc5283ad4 ]
In the ether3_probe function, a timer is initialized with a callback
function ether3_ledoff, bound to &prev(dev)->timer. Once the timer is
started, there is a risk of a race condition if the module or device
is removed, triggering the ether3_remove function to perform cleanup.
The sequence of operations that may lead to a UAF bug is as follows:
CPU0 CPU1
| ether3_ledoff
ether3_remove |
free_netdev(dev); |
put_devic |
kfree(dev); |
| ether3_outw(priv(dev)->regs.config2 |= CFG2_CTRLO, REG_CONFIG2);
| // use dev
Fix it by ensuring that the timer is canceled before proceeding with
the cleanup in ether3_remove.
Fixes: 6fd9c53f7186 ("net: seeq: Convert timers to use timer_setup()")
Signed-off-by: Kaixin Wang <kxwang23@xxxxxxxxxxxxxx>
Link: https://patch.msgid.link/20240915144045.451-1-kxwang23@xxxxxxxxxxxxxx
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/ethernet/seeq/ether3.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/net/ethernet/seeq/ether3.c b/drivers/net/ethernet/seeq/ether3.c
index 632a7c85964df..b057a38d3217a 100644
--- a/drivers/net/ethernet/seeq/ether3.c
+++ b/drivers/net/ethernet/seeq/ether3.c
@@ -848,9 +848,11 @@ static void ether3_remove(struct expansion_card *ec)
{
struct net_device *dev = ecard_get_drvdata(ec);
+ ether3_outw(priv(dev)->regs.config2 |= CFG2_CTRLO, REG_CONFIG2);
ecard_set_drvdata(ec, NULL);
unregister_netdev(dev);
+ del_timer_sync(&priv(dev)->timer);
free_netdev(dev);
ecard_release_resources(ec);
}
--
2.43.0
