watchdog: avoid usage of iterator after loop

If potentially no valid element is found, 'p' would contain an invalid
pointer past the iterator loop. To ensure 'p' is valid under any
circumstances, the kfree() should be within the loop body.

Additionally, Linus proposed to avoid any use of the list iterator
variable after the loop, in the attempt to move the list iterator
variable declaration into the macro to avoid any potential misuse after
the loop [1].

Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
Signed-off-by: Jakob Koschel <jkl820.git@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20230301-watchdog-avoid-iter-after-loop-v2-1-8411e3bbe0de@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
This commit is contained in:
Jakob Koschel 2023-03-13 14:59:19 +01:00 committed by Wim Van Sebroeck
parent fc0c5db58f
commit 33e4945352

View File

@ -207,10 +207,9 @@ void watchdog_unregister_pretimeout(struct watchdog_device *wdd)
list_for_each_entry_safe(p, t, &pretimeout_list, entry) {
if (p->wdd == wdd) {
list_del(&p->entry);
kfree(p);
break;
}
}
spin_unlock_irq(&pretimeout_lock);
kfree(p);
}