---

yaml --- r: 57940 b: refs/heads/master c: 06b32f3 h: refs/heads/master v: v3
git-mirror · Jun 21, 2007 · 03bdacc · 03bdacc
1 parent 2279152
commit 03bdacc
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Showing 2 changed files with 8 additions and 3 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: d2f1c0fa2b346769ac35559ae3bafccf151dd446
+refs/heads/master: 06b32f3ab6df4c7489729f94bdc7093c72681d4b
diff --git a/trunk/mm/mmap.c b/trunk/mm/mmap.c
@@ -1536,9 +1536,14 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
 	 * vma->vm_start/vm_end cannot change under us because the caller
 	 * is required to hold the mmap_sem in read mode.  We need the
 	 * anon_vma lock to serialize against concurrent expand_stacks.
+	 * Also guard against wrapping around to address 0.
 	 */
-	address += 4 + PAGE_SIZE - 1;
-	address &= PAGE_MASK;
+	if (address < PAGE_ALIGN(address+4))
+		address = PAGE_ALIGN(address+4);
+	else {
+		anon_vma_unlock(vma);
+		return -ENOMEM;
+	}
 	error = 0;
 
 	/* Somebody else might have raced and expanded it already */