Patch "[PATCH 075/135] hrtimer: Catch illegal clockids" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

[PATCH 075/135] hrtimer: Catch illegal clockids

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
0075-hrtimer-Catch-illegal-clockids.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Marc Zyngier <[email protected]>
Date: Fri, 15 Jan 2016 17:41:09 +0000
Subject: [PATCH 075/135] hrtimer: Catch illegal clockids

[ 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.

---
 kernel/time/hrtimer.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

@@ -94,6 +94,9 @@ DEFINE_PER_CPU(struct hrtimer_cpu_base,
 };
 
 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_t
 
 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;
 }
 
 /*

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/0070-arm64-KVM-Configure-TCR_EL2.PS-at-runtime.patch queue-4.4/0119-irqchip-gicv3-its-numa-Enable-workaround-for-Cavium-.patch queue-4.4/0069-irqchip-gic-v3-Make-sure-read-from-ICC_IAR1_EL1-is-v.patch queue-4.4/0075-hrtimer-Catch-illegal-clockids.patch