[PATCH] Fix strange size check in __get_vm_area_node()

[PATCH] Fix strange size check in __get_vm_area_node()

[OGAWA Hirofumi]

Recently, __get_vm_area_node() was changed like following

 	if (unlikely(!area))
 		return NULL;
 
-	if (unlikely(!size)) {
-		kfree (area);
+	if (unlikely(!size))
 		return NULL;
-	}

It is leaking `area', also original code seems strange already.
Probably, we wanted to do this patch.

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
---

 mm/vmalloc.c |    5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff -puN mm/vmalloc.c~vmalloc-leak-fix mm/vmalloc.c
--- linux-2.6/mm/vmalloc.c~vmalloc-leak-fix	2006-11-16 00:41:49.000000000 +0900
+++ linux-2.6-hirofumi/mm/vmalloc.c	2006-11-16 00:41:49.000000000 +0900
@@ -181,14 +181,13 @@ static struct vm_struct *__get_vm_area_n
 	}
 	addr = ALIGN(start, align);
 	size = PAGE_ALIGN(size);
+	if (unlikely(!size))
+		return NULL;
 
 	area = kmalloc_node(sizeof(*area), gfp_mask & GFP_LEVEL_MASK, node);
 	if (unlikely(!area))
 		return NULL;
 
-	if (unlikely(!size))
-		return NULL;
-
 	/*
 	 * We always allocate a guard page.
 	 */
_

-- 
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>

Re: [PATCH] Fix strange size check in __get_vm_area_node()

[Eric Dumazet]

On Wednesday 15 November 2006 18:39, OGAWA Hirofumi wrote:
> Recently, __get_vm_area_node() was changed like following
>
>  	if (unlikely(!area))
>  		return NULL;
>
> -	if (unlikely(!size)) {
> -		kfree (area);
> +	if (unlikely(!size))
>  		return NULL;
> -	}
>
> It is leaking `area', also original code seems strange already.
> Probably, we wanted to do this patch.
>

Indeed. I checked my original patch and it was correct. I dont know what 
happened then...

http://lkml.org/lkml/2006/10/23/86

Eric