This is a note to let you know that I've just added the patch titled
net: nfc: nci: Change the NCI close sequence
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-nfc-nci-change-the-nci-close-sequence.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 4ba29536100d2c098bb89cb061a391e417e35f62
Author: Bongsu Jeon <bongsu.jeon@xxxxxxxxxxx>
Date: Thu Dec 31 11:59:26 2020 +0900
net: nfc: nci: Change the NCI close sequence
[ Upstream commit f011539e723c737b74876ac47345e40270a3c384 ]
If there is a NCI command in work queue after closing the NCI device at
nci_unregister_device, The NCI command timer starts at flush_workqueue
function and then NCI command timeout handler would be called 5 second
after flushing the NCI command work queue and destroying the queue.
At that time, the timeout handler would try to use NCI command work queue
that is destroyed already. it will causes the problem. To avoid this
abnormal situation, change the sequence to prevent the NCI command timeout
handler from being called after destroying the NCI command work queue.
Signed-off-by: Bongsu Jeon <bongsu.jeon@xxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
index 5e55cb6c087a2..4d3ab0f44c9f4 100644
--- a/net/nfc/nci/core.c
+++ b/net/nfc/nci/core.c
@@ -568,11 +568,11 @@ static int nci_close_device(struct nci_dev *ndev)
clear_bit(NCI_INIT, &ndev->flags);
- del_timer_sync(&ndev->cmd_timer);
-
/* Flush cmd wq */
flush_workqueue(ndev->cmd_wq);
+ del_timer_sync(&ndev->cmd_timer);
+
/* Clear flags */
ndev->flags = 0;
