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Patch "arm: KVM: Fix VTTBR_BADDR_MASK BUG_ON off-by-one" has been added to the 3.18-stable tree

PATCH [email protected] 1 participant 2 messages Dec 14, 2017

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Stable branch Arm (32-bit)
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This is a note to let you know that I've just added the patch titled

arm: KVM: Fix VTTBR_BADDR_MASK BUG_ON off-by-one

to the 3.18-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:
arm-kvm-fix-vttbr_baddr_mask-bug_on-off-by-one.patch
and it can be found in the queue-3.18 subdirectory.

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

Quoted 1 line

From 5553b142be11e794ebc0805950b2e8313f93d718 Mon Sep 17 00:00:00 2001

From: Marc Zyngier <[email protected]>
Date: Thu, 16 Nov 2017 17:58:21 +0000
Subject: arm: KVM: Fix VTTBR_BADDR_MASK BUG_ON off-by-one

From: Marc Zyngier <[email protected]>

commit 5553b142be11e794ebc0805950b2e8313f93d718 upstream.

VTTBR_BADDR_MASK is used to sanity check the size and alignment of the VTTBR address. It seems to currently be off by one, thereby only allowing up to 39-bit addresses (instead of 40-bit) and also insufficiently checking the alignment. This patch fixes it.

This patch is the 32bit pendent of Kristina's arm64 fix, and she deserves the actual kudos for pinpointing that one.

Fixes f7ed45be3ba52 ("KVM: ARM: World-switch implementation")
Cc <[email protected]> # 3.9
Reported-by Kristina Martsenko <[email protected]>
Reviewed-by Christoffer Dall <[email protected]>
Signed-off-by Marc Zyngier <[email protected]>
Signed-off-by Christoffer Dall <[email protected]>
Signed-off-by Greg Kroah-Hartman <[email protected]>
---
 arch/arm/include/asm/kvm_arm.h |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
arch/arm/include/asm/kvm_arm.h +1 -2
@@ -161,8 +161,7 @@
 #else
 #define VTTBR_X		(5 - KVM_T0SZ)
 #endif
-#define VTTBR_BADDR_SHIFT (VTTBR_X - 1)
-#define VTTBR_BADDR_MASK  (((1LLU << (40 - VTTBR_X)) - 1) << VTTBR_BADDR_SHIFT)
+#define VTTBR_BADDR_MASK  (((1LLU << (40 - VTTBR_X)) - 1) << VTTBR_X)
 #define VTTBR_VMID_SHIFT  (48LLU)
 #define VTTBR_VMID_MASK	  (0xffLLU << VTTBR_VMID_SHIFT)

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

queue-3.18/arm-kvm-fix-vttbr_baddr_mask-bug_on-off-by-one.patch queue-3.18/arm-kvm-survive-unknown-traps-from-guests.patch queue-3.18/arm64-kvm-fix-vttbr_baddr_mask-bug_on-off-by-one.patch queue-3.18/irqchip-crossbar-fix-incorrect-type-of-register-size.patch

author maintainer
#1 lore raw
Quoted 11 lines · On Thu, Dec 14, 2017 at 09:46:39PM +0100, [email protected] wrote:

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

arm: KVM: Fix VTTBR_BADDR_MASK BUG_ON off-by-one

to the 3.18-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:
arm-kvm-fix-vttbr_baddr_mask-bug_on-off-by-one.patch
and it can be found in the queue-3.18 subdirectory.

Nope, I've dropped this, see my other email to Marc about this.

thanks,

greg k-h