[PATCH] mm/mmap: Avoid dereferencing next on null in BUG_ON()
From: Liam Howlett
Date: Thu May 19 2022 - 11:06:48 EST
Check there is a next before checking the bounds.
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
---
mm/mmap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/mmap.c b/mm/mmap.c
index 4279e2acd243..f1fc9c5c068b 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -583,7 +583,7 @@ inline int vma_expand(struct ma_state *mas, struct vm_area_struct *vma,
}
/* Not merging but overwriting any part of next is not handled. */
- VM_BUG_ON(!remove_next && next != vma && end > next->vm_start);
+ VM_BUG_ON(next && !remove_next && next != vma && end > next->vm_start);
/* Only handles expanding */
VM_BUG_ON(vma->vm_start < start || vma->vm_end > end);
--
2.35.1