[PATCH 5.10.y 2/2] ipmi:ssif: Clean up kthread on errors

[Corey Minyard <corey@minyard.net>]

If an error occurs after the ssif kthread is created, but before the
main IPMI code starts the ssif interface, the ssif kthread will not
be stopped.

So make sure the kthread is stopped on an error condition if it is
running.

Fixes: 259307074bfc ("ipmi: Add SMBus interface driver (SSIF)")
Reported-by: Li Xiao <<252270051@hdu.edu.cn>
Cc: stable@vger.kernel.org
Reviewed-by: Li Xiao <252270051@hdu.edu.cn>
Signed-off-by: Corey Minyard <corey@minyard.net>
(cherry picked from commit 75c486cb1bcaa1a3ec3a6438498176a3a4998ae4)
---
 drivers/char/ipmi/ipmi_ssif.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/char/ipmi/ipmi_ssif.c b/drivers/char/ipmi/ipmi_ssif.c
index 22074f23c06a..ce0f20cac88d 100644
--- a/drivers/char/ipmi/ipmi_ssif.c
+++ b/drivers/char/ipmi/ipmi_ssif.c
@@ -1277,8 +1277,10 @@ static void shutdown_ssif(void *send_info)
 	ssif_info->stopping = true;
 	del_timer_sync(&ssif_info->watch_timer);
 	del_timer_sync(&ssif_info->retry_timer);
-	if (ssif_info->thread)
+	if (ssif_info->thread) {
 		kthread_stop(ssif_info->thread);
+		ssif_info->thread = NULL;
+	}
 }
 
 static int ssif_remove(struct i2c_client *client)
@@ -1908,6 +1910,15 @@ static int ssif_probe(struct i2c_client *client, const struct i2c_device_id *id)
 
  out:
 	if (rv) {
+		/*
+		 * If ipmi_register_smi() starts the interface, it will
+		 * call shutdown and that will free the thread and set
+		 * it to NULL.  Otherwise it must be freed here.
+		 */
+		if (ssif_info->thread) {
+			kthread_stop(ssif_info->thread);
+			ssif_info->thread = NULL;
+		}
 		if (addr_info)
 			addr_info->client = NULL;
 
-- 
2.43.0