From b952caf2d5ca898cc10d63be7722ae7a5daca696 Mon Sep 17 00:00:00 2001 From: Qianli Zhao Date: Thu, 13 Aug 2020 23:03:14 +0800 Subject: timers: Mask invalid flags in do_init_timer() do_init_timer() accepts any combination of timer flags handed in by the caller without a sanity check, but only TIMER_DEFFERABLE, TIMER_PINNED and TIMER_IRQSAFE are valid. If the supplied flags have other bits set, this could result in malfunction. If bits are set in TIMER_CPUMASK the first timer usage could deference a cpu base which is outside the range of possible CPUs. If TIMER_MIGRATION is set, then the switch_timer_base() will live lock. Prevent that with a sanity check which warns when invalid flags are supplied and masks them out. [ tglx: Made it WARN_ON_ONCE() and added context to the changelog ] Signed-off-by: Qianli Zhao Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/9d79a8aa4eb56713af7379f99f062dedabcde140.1597326756.git.zhaoqianli@xiaomi.com --- include/linux/timer.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/timer.h') diff --git a/include/linux/timer.h b/include/linux/timer.h index 07910ae5ddd9..d10bc7e73b41 100644 --- a/include/linux/timer.h +++ b/include/linux/timer.h @@ -67,6 +67,7 @@ struct timer_list { #define TIMER_DEFERRABLE 0x00080000 #define TIMER_PINNED 0x00100000 #define TIMER_IRQSAFE 0x00200000 +#define TIMER_INIT_FLAGS (TIMER_DEFERRABLE | TIMER_PINNED | TIMER_IRQSAFE) #define TIMER_ARRAYSHIFT 22 #define TIMER_ARRAYMASK 0xFFC00000 -- cgit v1.2.3