From: Marc Zyngier <marc.zyngier@xxxxxxx> [ Upstream commit 9006a01829a50cfd6bbd4980910ed46e895e93d7 ] It is way too easy to take any random clockid and feed it to the hrtimer subsystem. At best, it gets mapped to a monotonic base, but it would be better to just catch illegal values as early as possible. This patch does exactly that, mapping illegal clockids to an illegal base index, and panicing when we detect the illegal condition. Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx> Cc: Tomasz Nowicki <tn@xxxxxxxxxxxx> Cc: Christoffer Dall <christoffer.dall@xxxxxxxxxx> Link: http://lkml.kernel.org/r/1452879670-16133-3-git-send-email-marc.zyngier@xxxxxxx Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> --- kernel/time/hrtimer.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index fa909f9..17f7bcf 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -94,6 +94,9 @@ DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) = }; static const int hrtimer_clock_to_base_table[MAX_CLOCKS] = { + /* Make sure we catch unsupported clockids */ + [0 ... MAX_CLOCKS - 1] = HRTIMER_MAX_CLOCK_BASES, + [CLOCK_REALTIME] = HRTIMER_BASE_REALTIME, [CLOCK_MONOTONIC] = HRTIMER_BASE_MONOTONIC, [CLOCK_BOOTTIME] = HRTIMER_BASE_BOOTTIME, @@ -102,7 +105,9 @@ static const int hrtimer_clock_to_base_table[MAX_CLOCKS] = { static inline int hrtimer_clockid_to_base(clockid_t clock_id) { - return hrtimer_clock_to_base_table[clock_id]; + int base = hrtimer_clock_to_base_table[clock_id]; + BUG_ON(base == HRTIMER_MAX_CLOCK_BASES); + return base; } /* -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html