4.19-stable review patch. If anyone has any objections, please let me know.
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From: Kaixin Wang kxwang23@m.fudan.edu.cn
[ 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@m.fudan.edu.cn Link: https://patch.msgid.link/20240915144045.451-1-kxwang23@m.fudan.edu.cn Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 d1bb73bf99148..a612ca6418883 100644 --- a/drivers/net/ethernet/seeq/ether3.c +++ b/drivers/net/ethernet/seeq/ether3.c @@ -851,9 +851,11 @@ 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); }