[PATCH 3.15 64/84] DMA, CMA: fix possible memory leak

From: Greg Kroah-Hartman
Date: Tue Jul 15 2014 - 19:33:48 EST

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


From: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>

commit fe8eea4f4a3f299ef83ed090d5354698ebe4fda8 upstream.

We should free memory for bitmap when we find zone mismatch, otherwise
this memory will leak.

Additionally, I copy code comment from PPC KVM's CMA code to inform why
we need to check zone mis-match.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Acked-by: Zhang Yanfei <zhangyanfei@xxxxxxxxxxxxxx>
Reviewed-by: Michal Nazarewicz <mina86@xxxxxxxxxx>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Acked-by: Minchan Kim <minchan@xxxxxxxxxx>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Cc: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Cc: Michal Nazarewicz <mina86@xxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Gleb Natapov <gleb@xxxxxxxxxx>
Cc: Alexander Graf <agraf@xxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

drivers/base/dma-contiguous.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)

--- a/drivers/base/dma-contiguous.c
+++ b/drivers/base/dma-contiguous.c
@@ -155,13 +155,23 @@ static int __init cma_activate_area(stru
base_pfn = pfn;
for (j = pageblock_nr_pages; j; --j, pfn++) {
+ /*
+ * alloc_contig_range requires the pfn range
+ * specified to be in the same zone. Make this
+ * simple by forcing the entire CMA resv range
+ * to be in the same zone.
+ */
if (page_zone(pfn_to_page(pfn)) != zone)
- return -EINVAL;
+ goto err;
} while (--i);

return 0;
+ kfree(cma->bitmap);
+ return -EINVAL;

static struct cma cma_areas[MAX_CMA_AREAS];

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