[PATCH 4.4 077/117] iommu/io-pgtable-arm: Ensure we free the final level on teardown

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Will Deacon <will.deacon@xxxxxxx>

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@xxxxxxxxxx>
Signed-off-by: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 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++;


--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]