[PATCH RESEND] scsi: message: mptlan: Fix use after free bug in mptlan_remove due to race condition

From: Zheng Wang
Date: Thu Apr 13 2023 - 03:49:03 EST


In mptlan_probe, it called mpt_register_lan_device and bound
&priv->post_buckets_task with mpt_lan_post_receive_buckets_work.
When it calls lan_reply, it will finally call
mpt_lan_wake_post_buckets_task to start the work.

When we call mptlan_remove to remove the driver, there
may be a sequence as follows:

Fix it by finishing the work before cleanup in mptlan_remove

CPU0 CPU1

|mpt_lan_post_receive_buckets_work
mptlan_remove |
free_netdev |
kfree(dev); |
|
| dev->mtu
| //use

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Zheng Wang <zyytlz.wz@xxxxxxx>
---
drivers/message/fusion/mptlan.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/message/fusion/mptlan.c b/drivers/message/fusion/mptlan.c
index 142eb5d5d9df..de2e7bcf4784 100644
--- a/drivers/message/fusion/mptlan.c
+++ b/drivers/message/fusion/mptlan.c
@@ -1433,7 +1433,9 @@ mptlan_remove(struct pci_dev *pdev)
{
MPT_ADAPTER *ioc = pci_get_drvdata(pdev);
struct net_device *dev = ioc->netdev;
+ struct mpt_lan_priv *priv = netdev_priv(dev);

+ cancel_delayed_work_sync(&priv->post_buckets_task);
if(dev != NULL) {
unregister_netdev(dev);
free_netdev(dev);
--
2.25.1