blkdev.h integer overflows

PATCH William Lee Irwin III 1 participant 1 message Dec 23, 2002 Block layer

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William Lee Irwin III

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2002-12-23 16:10 UTC #0 lore raw

blk_max_pfn is an unsigned long; left shifting by PAGE_SHIFT means it may overflow.

Bill

include/linux/blkdev.h +2 -2

diff -urpN mm2-2.5.52-1/include/linux/blkdev.h blk-2.5.52-1/include/linux/blkdev.h
@@ -297,8 +297,8 @@ extern unsigned long blk_max_low_pfn, bl
  * BLK_BOUNCE_ANY	: don't bounce anything
  * BLK_BOUNCE_ISA	: bounce pages above ISA DMA boundary
  */
-#define BLK_BOUNCE_HIGH		(blk_max_low_pfn << PAGE_SHIFT)
-#define BLK_BOUNCE_ANY		(blk_max_pfn << PAGE_SHIFT)
+#define BLK_BOUNCE_HIGH		((u64)blk_max_low_pfn << PAGE_SHIFT)
+#define BLK_BOUNCE_ANY		((u64)blk_max_pfn << PAGE_SHIFT)
 #define BLK_BOUNCE_ISA		(ISA_DMA_THRESHOLD)
 
 extern int init_emergency_isa_pool(void);