2015-11-02 08:39:23

by kernel test robot

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Subject: [lkp] [iommu/vt] a13c8f27e4: DMAR-IR: Failed to enable irq remapping. You are vulnerable to irq-injection attacks.

FYI, we noticed the below changes on

https://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu.git x86/vt-d
commit a13c8f27e4d79420ae7bcb48123fa13851026428 ("iommu/vt-d: Adjust the return value of the parse_ioapics_under_ir")

We found the following new message in kernel log.

[ 0.126325] DMAR-IR: Failed to enable irq remapping. You are vulnerable to irq-injection attacks.


To reproduce:

git clone git://git.kernel.org/pub/scm/linux/kernel/git/wfg/lkp-tests.git
cd lkp-tests
bin/lkp install job.yaml # job file is attached in this email
bin/lkp run job.yaml



Thanks,
Ying Huang

Attachments:
(No filename) (627.00 B)
 config-4.3.0-rc3-00005-ga13c8f2 (138.26 kB)
 kmsg.xz (21.95 kB)
 job.yaml (3.14 kB)
 reproduce (1.17 kB)
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2015-11-02 11:00:21

by Jörg Rödel

[permalink] [raw]
Subject: [PATCH] iommu/vt-d: Fix return value check of parse_ioapics_under_ir()

On Mon, Nov 02, 2015 at 04:39:18PM +0800, kernel test robot wrote:
> FYI, we noticed the below changes on
>
> https://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu.git x86/vt-d
> commit a13c8f27e4d79420ae7bcb48123fa13851026428 ("iommu/vt-d: Adjust the return value of the parse_ioapics_under_ir")
>
> We found the following new message in kernel log.
>
> [ 0.126325] DMAR-IR: Failed to enable irq remapping. You are vulnerable to irq-injection attacks.

Thanks for the report, I just queued the fix below.

>From b61e5e80e3cd37f0183cdc04b03861a0467d9f52 Mon Sep 17 00:00:00 2001
From: Joerg Roedel <[email protected]>
Date: Mon, 2 Nov 2015 19:57:31 +0900
Subject: [PATCH] iommu/vt-d: Fix return value check of parse_ioapics_under_ir()

The function returns 0 on success, so check for the right
value.

Signed-off-by: Joerg Roedel <[email protected]>
---
drivers/iommu/intel_irq_remapping.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/intel_irq_remapping.c b/drivers/iommu/intel_irq_remapping.c
index f3a9bd1..1fae188 100644
--- a/drivers/iommu/intel_irq_remapping.c
+++ b/drivers/iommu/intel_irq_remapping.c
@@ -690,7 +690,7 @@ static int __init intel_prepare_irq_remapping(void)
if (!dmar_ir_support())
return -ENODEV;

- if (!parse_ioapics_under_ir()) {
+ if (parse_ioapics_under_ir()) {
pr_info("Not enabling interrupt remapping\n");
goto error;
}
--
1.8.4.5