Patch "iommu/amd: Fix incorrect error handling in amd_iommu_bind_pasid()" has been added to the 4.4-stable tree

[<gregkh@linuxfoundation.org>]

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

    iommu/amd: Fix incorrect error handling in amd_iommu_bind_pasid()

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:
     iommu-amd-fix-incorrect-error-handling-in-amd_iommu_bind_pasid.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 <stable@vger.kernel.org> know about it.


>From 73dbd4a4230216b6a5540a362edceae0c9b4876b Mon Sep 17 00:00:00 2001
From: Pan Bian <bianpan2016@163.com>
Date: Sun, 23 Apr 2017 18:23:21 +0800
Subject: iommu/amd: Fix incorrect error handling in amd_iommu_bind_pasid()

From: Pan Bian <bianpan2016@163.com>

commit 73dbd4a4230216b6a5540a362edceae0c9b4876b upstream.

In function amd_iommu_bind_pasid(), the control flow jumps
to label out_free when pasid_state->mm and mm is NULL. And
mmput(mm) is called.  In function mmput(mm), mm is
referenced without validation. This will result in a NULL
dereference bug. This patch fixes the bug.

Signed-off-by: Pan Bian <bianpan2016@163.com>
Fixes: f0aac63b873b ('iommu/amd: Don't hold a reference to mm_struct')
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/iommu/amd_iommu_v2.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/iommu/amd_iommu_v2.c
+++ b/drivers/iommu/amd_iommu_v2.c
@@ -699,9 +699,9 @@ out_clear_state:
 
 out_unregister:
 	mmu_notifier_unregister(&pasid_state->mn, mm);
+	mmput(mm);
 
 out_free:
-	mmput(mm);
 	free_pasid_state(pasid_state);
 
 out:


Patches currently in stable-queue which might be from bianpan2016@163.com are

queue-4.4/iommu-amd-fix-incorrect-error-handling-in-amd_iommu_bind_pasid.patch