Patch "iommu/io-pgtable-arm: Ensure we free the final level on teardown" has been added to the 4.3-stable tree

Patch "iommu/io-pgtable-arm: Ensure we free the final level on teardown" has been added to the 4.3-stable tree

[gregkh]

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

    iommu/io-pgtable-arm: Ensure we free the final level on teardown

to the 4.3-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-io-pgtable-arm-ensure-we-free-the-final-level-on-teardown.patch
and it can be found in the queue-4.3 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 12c2ab09571e8aae3a87da2a4a452632a5fac1e5 Mon Sep 17 00:00:00 2001
From: Will Deacon <will.deacon@arm.com>
Date: Tue, 15 Dec 2015 16:08:12 +0000
Subject: iommu/io-pgtable-arm: Ensure we free the final level on teardown

From: Will Deacon <will.deacon@arm.com>

commit 12c2ab09571e8aae3a87da2a4a452632a5fac1e5 upstream.

When tearing down page tables, we return early for the final level
since we know that we won't have any table pointers to follow.
Unfortunately, this also means that we forget to free the final level,
so we end up leaking memory.

Fix the issue by always freeing the current level, but just don't bother
to iterate over the ptes if we're at the final level.

Reported-by: Zhang Bo <zhangbo_a@xiaomi.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/iommu/io-pgtable-arm.c |   11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -405,17 +405,18 @@ static void __arm_lpae_free_pgtable(stru
 	arm_lpae_iopte *start, *end;
 	unsigned long table_size;
 
-	/* Only leaf entries at the last level */
-	if (lvl == ARM_LPAE_MAX_LEVELS - 1)
-		return;
-
 	if (lvl == ARM_LPAE_START_LVL(data))
 		table_size = data->pgd_size;
 	else
 		table_size = 1UL << data->pg_shift;
 
 	start = ptep;
-	end = (void *)ptep + table_size;
+
+	/* Only leaf entries at the last level */
+	if (lvl == ARM_LPAE_MAX_LEVELS - 1)
+		end = ptep;
+	else
+		end = (void *)ptep + table_size;
 
 	while (ptep != end) {
 		arm_lpae_iopte pte = *ptep++;


Patches currently in stable-queue which might be from will.deacon@arm.com are

queue-4.3/iommu-io-pgtable-arm-ensure-we-free-the-final-level-on-teardown.patch