[PATCH 0/1] char: Use list_del_init() in misc_deregister()
xion.wang at mediatek.com
xion.wang at mediatek.com
Wed Sep 3 23:37:03 PDT 2025
From: Xion Wang <xion.wang at mediatek.com>
Hi all,
This patch updates the misc_deregister() function to use list_del_init()
instead of list_del() when removing the device from the list.
While list_del() poisons the list pointers to catch invalid usage,
it does not reset the list head.
If misc_deregister() is called more than once on the same device,
list_empty() will not return true and list_del() may be called again,
leading to undefined behavior.
By switching to list_del_init(), we ensure the list head is reinitialized,
making the code more robust against double deregistration and
allowing safe usage of list_empty() after deregistration.
Fixes: b329becfc78b1 ("char: add WARN_ON() in misc_deregister()")
Let me know if you have any questions or suggestions.
Thanks,
Xion Wang
Xion Wang (1):
char: Use list_del_init() in misc_deregister() to reinitialize list
pointer
drivers/char/misc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--
2.45.2
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