On Fri, Oct 18, 2024 at 09:54:28PM +0800, He Zhe wrote:
From: Duoming Zhou duoming@zju.edu.cn
commit 573601521277119f2e2ba5f28ae6e87fc594f4d4 upstream.
When the cpu5wdt module is removing, the origin code uses del_timer() to de-activate the timer. If the timer handler is running, del_timer() could not stop it and will return directly. If the port region is released by release_region() and then the timer handler cpu5wdt_trigger() calls outb() to write into the region that is released, the use-after-free bug will happen.
Change del_timer() to timer_shutdown_sync() in order that the timer handler could be finished before the port region is released.
Fixes: e09d9c3e9f85 ("watchdog: cpu5wdt.c: add missing del_timer call") Signed-off-by: Duoming Zhou duoming@zju.edu.cn Reviewed-by: Guenter Roeck linux@roeck-us.net Link: https://lore.kernel.org/r/20240324140444.119584-1-duoming@zju.edu.cn Signed-off-by: Guenter Roeck linux@roeck-us.net Signed-off-by: Wim Van Sebroeck wim@linux-watchdog.org
CVE: CVE-2024-38630
[Zhe: The function timer_shutdown_sync in the original fix is not introduced to 5.10 yet. As stated in f571faf6e443b6011ccb585d57866177af1f643c
Please refer to commits in the correct way, this would be f571faf6e443 ("timers: Provide timer_shutdown[_sync]()"), right?
thanks,
greg k-h