[Devel] [PATCH vz7] devtmpfs: fix the dangling pointer of global devtmpfsd thread

[Alexander Atanasov]

When the devtmpfs fails to mount, a dangling pointer still remains in
global. Specifically, the err variable is passed by a pointer to the
devtmpfsd. When the devtmpfsd exits, it sets the error and completes the
setup_done. In this situation, the thread pointer is not set to null.
After the devtmpfsd exited, the devtmpfs can wakes up the destroyed
devtmpfsd thread by wake_up_process if a device change event comes.

 Signed-off-by: Yangxi Xiang <xyangxi5 at gmail.com>
 Link: https://lore.kernel.org/r/20220627120409.11174-1-xyangxi5@gmail.com
 Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>

(mainstream commit 31c779f293b343577690c01369a5019ca6ec5de9)
https://jira.sw.ru/browse/PSBM-142996
Signed-off-by: Alexander Atanasov <alexander.atanasov at virtuozzo.com>
---
 drivers/base/devtmpfs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c
index 8aefc2dc63a1..eb064072414a 100644
--- a/drivers/base/devtmpfs.c
+++ b/drivers/base/devtmpfs.c
@@ -485,12 +485,12 @@ int __init devtmpfs_init(void)
 		wait_for_completion(&setup_done);
 	} else {
 		err = PTR_ERR(thread);
-		thread = NULL;
 	}
 
 	if (err) {
 		printk(KERN_ERR "devtmpfs: unable to create devtmpfs %i\n", err);
 		unregister_filesystem(&dev_fs_type);
+		thread = NULL;
 		return err;
 	}
 
-- 
2.31.1