Re: mm: kernel BUG at mm/mempolicy.c:1203!

[Bob Liu <bob.liu@oracle.com>]

On 12/16/2013 07:37 AM, Sasha Levin wrote:
> Hi all,
> 
> While fuzzing with trinity inside a KVM tools guest running latest -next
> kernel, I've
> stumbled on the following spew.
> 
> This seems to be due to commit 0bf598d863e "mbind: add BUG_ON(!vma) in
> new_vma_page()"
> which added that BUG_ON.

Could you take a try with this patch from Wanpeng Li?

Thanks,
-Bob

Subject: [PATCH] mm/mempolicy: fix !vma in new_vma_page()
....
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
index eca4a31..73b5a35 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1197,14 +1197,16 @@ static struct page *new_vma_page(struct page
*page, unsigned long private, int *
 			break;
 		vma = vma->vm_next;
 	}
+
+	if (PageHuge(page)) {
+		if (vma)
+			return alloc_huge_page_noerr(vma, address, 1);
+		else
+			return NULL;
+	}
 	/*
-	 * queue_pages_range() confirms that @page belongs to some vma,
-	 * so vma shouldn't be NULL.
+	 * if !vma, alloc_page_vma() will use task or system default policy
 	 */
-	BUG_ON(!vma);
-
-	if (PageHuge(page))
-		return alloc_huge_page_noerr(vma, address, 1);
 	return alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
 }
 #else

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