[PATCH] xfs: Fix uninitialized return value in xfs_alloc_fix_freelist()

[PATCH] xfs: Fix uninitialized return value in xfs_alloc_fix_freelist()

[Jan Kara]

xfs_alloc_fix_freelist() can sometimes jump to out_agbp_relse without
ever setting value of 'error' variable which is then returned. This can
happen e.g. when pag->pagf_init is set but AG is for metadata and we
want to allocate user data.

Fix the problem by initializing 'error' to 0, which is the desired
return value when we decide to skip this group.

CC: xfs@oss.sgi.com
Coverity-id: 1309714
Signed-off-by: Jan Kara <jack@suse.com>
---
 fs/xfs/libxfs/xfs_alloc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
index f9e9ffe6fb46..7f8f2a0d4567 100644
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -1937,7 +1937,7 @@ xfs_alloc_fix_freelist(
 	struct xfs_alloc_arg	targs;	/* local allocation arguments */
 	xfs_agblock_t		bno;	/* freelist block */
 	xfs_extlen_t		need;	/* total blocks needed in freelist */
-	int			error;
+	int			error = 0;
 
 	if (!pag->pagf_init) {
 		error = xfs_alloc_read_agf(mp, tp, args->agno, flags, &agbp);
-- 
2.1.4

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Re: [PATCH] xfs: Fix uninitialized return value in xfs_alloc_fix_freelist()

[Brian Foster]

On Wed, Jul 15, 2015 at 10:16:08AM +0200, Jan Kara wrote:
> xfs_alloc_fix_freelist() can sometimes jump to out_agbp_relse without
> ever setting value of 'error' variable which is then returned. This can
> happen e.g. when pag->pagf_init is set but AG is for metadata and we
> want to allocate user data.
> 
> Fix the problem by initializing 'error' to 0, which is the desired
> return value when we decide to skip this group.
> 
> CC: xfs@oss.sgi.com
> Coverity-id: 1309714
> Signed-off-by: Jan Kara <jack@suse.com>
> ---

Reviewed-by: Brian Foster <bfoster@redhat.com>

>  fs/xfs/libxfs/xfs_alloc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
> index f9e9ffe6fb46..7f8f2a0d4567 100644
> --- a/fs/xfs/libxfs/xfs_alloc.c
> +++ b/fs/xfs/libxfs/xfs_alloc.c
> @@ -1937,7 +1937,7 @@ xfs_alloc_fix_freelist(
>  	struct xfs_alloc_arg	targs;	/* local allocation arguments */
>  	xfs_agblock_t		bno;	/* freelist block */
>  	xfs_extlen_t		need;	/* total blocks needed in freelist */
> -	int			error;
> +	int			error = 0;
>  
>  	if (!pag->pagf_init) {
>  		error = xfs_alloc_read_agf(mp, tp, args->agno, flags, &agbp);
> -- 
> 2.1.4
> 
> _______________________________________________
> xfs mailing list
> xfs@oss.sgi.com
> http://oss.sgi.com/mailman/listinfo/xfs

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Re: [PATCH] xfs: Fix uninitialized return value in xfs_alloc_fix_freelist()

[Eric Sandeen]

On 7/15/15 6:16 AM, Brian Foster wrote:
> On Wed, Jul 15, 2015 at 10:16:08AM +0200, Jan Kara wrote:
>> xfs_alloc_fix_freelist() can sometimes jump to out_agbp_relse without
>> ever setting value of 'error' variable which is then returned. This can
>> happen e.g. when pag->pagf_init is set but AG is for metadata and we
>> want to allocate user data.
>>
>> Fix the problem by initializing 'error' to 0, which is the desired
>> return value when we decide to skip this group.
>>
>> CC: xfs@oss.sgi.com
>> Coverity-id: 1309714
>> Signed-off-by: Jan Kara <jack@suse.com>
>> ---
> 
> Reviewed-by: Brian Foster <bfoster@redhat.com>

Dave, ping on this one?  I don't see it in your latest update, looks important.
(xfsprogs has the same problem, FWIW)

-Eric

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