Commit 67a2e213 authored by Rohit Vaswani's avatar Rohit Vaswani Committed by Linus Torvalds
Browse files

mm: cma: fix incorrect type conversion for size during dma allocation 



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: default avatarRohit Vaswani <rvaswani@codeaurora.org>
Acked-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 52116139

drivers/base/dma-contiguous.c

+1 −1
Original line number Diff line number Diff line
@@ -187,7 +187,7 @@ int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base, 
 * 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)

include/linux/cma.h

+1 −1
Original line number Diff line number Diff line
@@ -26,6 +26,6 @@ extern int __init cma_declare_contiguous(phys_addr_t base, 
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

include/linux/dma-contiguous.h

+2 −2
Original line number Diff line number Diff line
@@ -111,7 +111,7 @@ static inline int dma_declare_contiguous(struct device *dev, phys_addr_t size, 
	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 *dev, phys_addr_t size, 
}



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;

mm/cma.c

+2 −2
Original line number Diff line number Diff line
@@ -361,7 +361,7 @@ 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;
@@ -371,7 +371,7 @@ struct page *cma_alloc(struct cma *cma, unsigned int count, unsigned int align) 
	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)

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