Avoid mmap() overflow case if TASK_SIZE is the

full range of an "unsigned long" (sparc64).

Avoid mmap() overflow case if TASK_SIZE is the
full range of an "unsigned long" (sparc64).
ee4cad49 · Linus Torvalds · 06dd43c4 · ee4cad49
Commit ee4cad49 authored Jul 10, 2003 by Linus Torvalds
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mm/mmap.c mm/mmap.c +3 -3

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--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -476,10 +476,10 @@ unsigned long do_mmap_pgoff(struct file * file, unsigned long addr,
 	if (!len)
 		return addr;

-	if (len > TASK_SIZE)
-		return -EINVAL;
-
+	/* Careful about overflows.. */
 	len = PAGE_ALIGN(len);
+	if (!len || len > TASK_SIZE)
+		return -EINVAL;

 	/* offset overflow? */
 	if ((pgoff + (len >> PAGE_SHIFT)) < pgoff)