From: Greg Edwards <gedwards@ddn.com>
To: Joerg Roedel <joro@8bytes.org>, David Woodhouse <dwmw2@infradead.org>
Cc: <iommu@lists.linux-foundation.org>, <linux-kernel@vger.kernel.org>
Subject: [PATCH] iommu/vt-d: fix race between free_irte() and get_irte()
Date: Tue, 22 Jul 2014 08:27:19 -0600 [thread overview]
Message-ID: <20140722142719.GA28143@psuche.datadirectnet.com> (raw)
get_irte() can race with free_irte() and dereference a NULL iommu
pointer.
Signed-off-by: Greg Edwards <gedwards@ddn.com>
Cc: stable@vger.kernel.org
---
drivers/iommu/intel_irq_remapping.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/iommu/intel_irq_remapping.c b/drivers/iommu/intel_irq_remapping.c
index 9b17489..2d67e6d 100644
--- a/drivers/iommu/intel_irq_remapping.c
+++ b/drivers/iommu/intel_irq_remapping.c
@@ -70,6 +70,12 @@ static int get_irte(int irq, struct irte *entry)
raw_spin_lock_irqsave(&irq_2_ir_lock, flags);
+ /* ensure we're not racing with free_irte() */
+ if (unlikely(!irq_iommu->iommu)) {
+ raw_spin_unlock_irqrestore(&irq_2_ir_lock, flags);
+ return -1;
+ }
+
index = irq_iommu->irte_index + irq_iommu->sub_handle;
*entry = *(irq_iommu->iommu->ir_table->base + index);
--
1.9.3
next reply other threads:[~2014-07-22 14:32 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-22 14:27 Greg Edwards [this message]
2014-07-23 14:40 ` [PATCH] iommu/vt-d: fix race between free_irte() and get_irte() Joerg Roedel
2014-07-23 14:49 ` Greg Edwards
2014-07-23 15:10 ` Joerg Roedel
2014-07-23 16:13 ` [PATCH v2] iommu/vt-d: race setting IRQ CPU affinity while freeing IRQ Greg Edwards
2014-07-29 10:45 ` Joerg Roedel
2014-07-29 17:21 ` Greg Edwards
2014-07-31 11:49 ` Joerg Roedel
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20140722142719.GA28143@psuche.datadirectnet.com \
--to=gedwards@ddn.com \
--cc=dwmw2@infradead.org \
--cc=iommu@lists.linux-foundation.org \
--cc=joro@8bytes.org \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).