[PATCH 3.18 15/24] mm: cma: fix incorrect type conversion for size during dma allocation

Greg Kroah-Hartman
2017-08-31T15:44:24Z

From: Rohit Vaswani <rvaswani@codeaurora.org>

commit 67a2e213e7e937c41c52ab5bc46bf3f4de469f6e upstream.

This was found during userspace fuzzing test when a large size dma cma
allocation is made by driver(like ion) through userspace.

show_stack+0x10/0x1c
dump_stack+0x74/0xc8
kasan_report_error+0x2b0/0x408
kasan_report+0x34/0x40
__asan_storeN+0x15c/0x168
memset+0x20/0x44
__dma_alloc_coherent+0x114/0x18c

Signed-off-by: Rohit Vaswani <rvaswani@codeaurora.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Miles Chen <miles.chen@mediatek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/base/dma-contiguous.c | 2 +-
include/linux/cma.h | 2 +-
include/linux/dma-contiguous.h | 4 ++--
mm/cma.c | 4 ++--
4 files changed, 6 insertions(+), 6 deletions(-)

--- a/drivers/base/dma-contiguous.c
+++ b/drivers/base/dma-contiguous.c
@@ -187,7 +187,7 @@ int __init dma_contiguous_reserve_area(p
* global one. Requires architecture specific dev_get_cma_area() helper
* function.
*/
-struct page *dma_alloc_from_contiguous(struct device *dev, int count,
+struct page *dma_alloc_from_contiguous(struct device *dev, size_t count,
unsigned int align)
{
if (align > CONFIG_CMA_ALIGNMENT)
--- a/include/linux/cma.h
+++ b/include/linux/cma.h
@@ -26,6 +26,6 @@ extern int __init cma_declare_contiguous
extern int cma_init_reserved_mem(phys_addr_t base, phys_addr_t size,
unsigned int order_per_bit,
struct cma **res_cma);
-extern struct page *cma_alloc(struct cma *cma, unsigned int count, unsigned int align);
+extern struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align);
extern bool cma_release(struct cma *cma, const struct page *pages, unsigned int count);
#endif
--- a/include/linux/dma-contiguous.h
+++ b/include/linux/dma-contiguous.h
@@ -111,7 +111,7 @@ static inline int dma_declare_contiguous
return ret;
}

-struct page *dma_alloc_from_contiguous(struct device *dev, int count,
+struct page *dma_alloc_from_contiguous(struct device *dev, size_t count,
unsigned int order);
bool dma_release_from_contiguous(struct device *dev, struct page *pages,
int count);
@@ -144,7 +144,7 @@ int dma_declare_contiguous(struct device
}

static inline
-struct page *dma_alloc_from_contiguous(struct device *dev, int count,
+struct page *dma_alloc_from_contiguous(struct device *dev, size_t count,
unsigned int order)
{
return NULL;
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -363,7 +363,7 @@ err:
* This function allocates part of contiguous memory on specific
* contiguous memory area.
*/
-struct page *cma_alloc(struct cma *cma, unsigned int count, unsigned int align)
+struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align)
{
unsigned long mask, offset, pfn, start = 0;
unsigned long bitmap_maxno, bitmap_no, bitmap_count;
@@ -373,7 +373,7 @@ struct page *cma_alloc(struct cma *cma,
if (!cma || !cma->count)
return NULL;

- pr_debug("%s(cma %p, count %d, align %d)\n", __func__, (void *)cma,
+ pr_debug("%s(cma %p, count %zu, align %d)\n", __func__, (void *)cma,
count, align);

if (!count)