mm: usercopy: move the virt_addr_valid() below the is_vmalloc_addr()

The is_kmap_addr() and the is_vmalloc_addr() in the check_heap_object() will not work, because the virt_addr_valid() will exclude the kmap and vmalloc regions. So let's move the virt_addr_valid() below the is_vmalloc_addr(). Signed-off-by: Yuanzheng Song <[email protected]> Fixes: 4e140f5 ("mm/usercopy: Check kmap addresses properly") Fixes: 0aef499 ("mm/usercopy: Detect vmalloc overruns") Cc: Matthew Wilcox (Oracle) <[email protected]> Signed-off-by: Kees Cook <[email protected]> Link: https://lore.kernel.org/r/[email protected]
ambv · May 16, 2022 · a5f4d9d · a5f4d9d
1 parent 710e4eb
commit a5f4d9d
Showing 1 changed file with 3 additions and 3 deletions.
diff --git a/mm/usercopy.c b/mm/usercopy.c
@@ -163,9 +163,6 @@ static inline void check_heap_object(const void *ptr, unsigned long n,
 {
 	struct folio *folio;
 
-	if (!virt_addr_valid(ptr))
-		return;
-
 	if (is_kmap_addr(ptr)) {
 		unsigned long page_end = (unsigned long)ptr | (PAGE_SIZE - 1);
 
@@ -190,6 +187,9 @@ static inline void check_heap_object(const void *ptr, unsigned long n,
 		return;
 	}
 
+	if (!virt_addr_valid(ptr))
+		return;
+
 	folio = virt_to_folio(ptr);
 
 	if (folio_test_slab(folio)) {