[PATCH] xfs: fix memory leak on error in xfs_alloc_zone_info()

[PATCH] xfs: fix memory leak on error in xfs_alloc_zone_info()

[Wilfred Mallawa]

From: Wilfred Mallawa <wilfred.mallawa@wdc.com>

Currently, the 0th index of the zi_used_bucket_bitmap array is not freed on
error due to the pre-decrement then evaluate semantic of this while loop used
in xfs_alloc_zone_info(). Fix it by allowing for the i == 0 case to be covered.

Signed-off-by: Wilfred Mallawa <wilfred.mallawa@wdc.com>
Fixes: 080d01c41d44 ("xfs: implement zoned garbage collection")
Cc: stable@vger.kernel.org
---
 fs/xfs/xfs_zone_alloc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/xfs/xfs_zone_alloc.c b/fs/xfs/xfs_zone_alloc.c
index a851b98143c0..c64f9ab743a6 100644
--- a/fs/xfs/xfs_zone_alloc.c
+++ b/fs/xfs/xfs_zone_alloc.c
@@ -1217,7 +1217,7 @@ xfs_alloc_zone_info(
 	return zi;
 
 out_free_bitmaps:
-	while (--i > 0)
+	while (--i >= 0)
 		kvfree(zi->zi_used_bucket_bitmap[i]);
 	kfree(zi);
 	return NULL;
-- 
2.53.0

Re: [PATCH] xfs: fix memory leak on error in xfs_alloc_zone_info()

[Damien Le Moal]

On 2026/04/14 5:41, Wilfred Mallawa wrote:
> From: Wilfred Mallawa <wilfred.mallawa@wdc.com>
> 
> Currently, the 0th index of the zi_used_bucket_bitmap array is not freed on
> error due to the pre-decrement then evaluate semantic of this while loop used

s/this/the

> in xfs_alloc_zone_info(). Fix it by allowing for the i == 0 case to be covered.

Please limit your commit message text to 74 chars per line.
(See Documentation/process/submitting-patches.rst, "The canonical patch format"
section).

> Signed-off-by: Wilfred Mallawa <wilfred.mallawa@wdc.com>

I think that the usual order here is to have the Fixes and CC tag before your
signed-off-by.

> Fixes: 080d01c41d44 ("xfs: implement zoned garbage collection")
> Cc: stable@vger.kernel.org

Other than this, looks good to me.

Reviewed-by: Damien Le Moal <dlemoal@kernel.org>

> ---
>  fs/xfs/xfs_zone_alloc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/xfs/xfs_zone_alloc.c b/fs/xfs/xfs_zone_alloc.c
> index a851b98143c0..c64f9ab743a6 100644
> --- a/fs/xfs/xfs_zone_alloc.c
> +++ b/fs/xfs/xfs_zone_alloc.c
> @@ -1217,7 +1217,7 @@ xfs_alloc_zone_info(
>  	return zi;
>  
>  out_free_bitmaps:
> -	while (--i > 0)
> +	while (--i >= 0)
>  		kvfree(zi->zi_used_bucket_bitmap[i]);
>  	kfree(zi);
>  	return NULL;


-- 
Damien Le Moal
Western Digital Research

Re: [PATCH] xfs: fix memory leak on error in xfs_alloc_zone_info()

[Carlos Maiolino]

On Tue, Apr 14, 2026 at 01:41:51PM +1000, Wilfred Mallawa wrote:
> From: Wilfred Mallawa <wilfred.mallawa@wdc.com>
> 
> Currently, the 0th index of the zi_used_bucket_bitmap array is not freed on
> error due to the pre-decrement then evaluate semantic of this while loop used
> in xfs_alloc_zone_info(). Fix it by allowing for the i == 0 case to be covered.
> 
> Signed-off-by: Wilfred Mallawa <wilfred.mallawa@wdc.com>
> Fixes: 080d01c41d44 ("xfs: implement zoned garbage collection")
> Cc: stable@vger.kernel.org

Code looks good.

After fixing Damien's suggestions, feel free to add:
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>

> ---
>  fs/xfs/xfs_zone_alloc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/xfs/xfs_zone_alloc.c b/fs/xfs/xfs_zone_alloc.c
> index a851b98143c0..c64f9ab743a6 100644
> --- a/fs/xfs/xfs_zone_alloc.c
> +++ b/fs/xfs/xfs_zone_alloc.c
> @@ -1217,7 +1217,7 @@ xfs_alloc_zone_info(
>  	return zi;
>  
>  out_free_bitmaps:
> -	while (--i > 0)
> +	while (--i >= 0)
>  		kvfree(zi->zi_used_bucket_bitmap[i]);
>  	kfree(zi);
>  	return NULL;
> -- 
> 2.53.0
> 
>