Re: [PATCH] btrfs: fix memory leak when rejecting a non SINGLE data profile without an RST

From: Johannes Thumshirn

Date: Tue Oct 07 2025 - 06:13:21 EST


On 10/7/25 7:55 AM, Miquel Sabaté Solà wrote:
> At the end of btrfs_load_block_group_zone_info() the first thing we do
> is to ensure that if the mapping type is not a SINGLE one and there is
> no RAID stripe tree, then we return early with an error.
>
> Doing that, though, prevents the code from running the last calls from
> this function which are about freeing memory allocated during its
> run. Hence, in this case, instead of returning early go to the freeing
> section of this function and leave then.
>
> Signed-off-by: Miquel Sabaté Solà <mssola@xxxxxxxxxx>
> ---
> fs/btrfs/zoned.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
> index e3341a84f4ab..b0f5d61dbfd2 100644
> --- a/fs/btrfs/zoned.c
> +++ b/fs/btrfs/zoned.c
> @@ -1753,7 +1753,8 @@ int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache, bool new)
> !fs_info->stripe_root) {
> btrfs_err(fs_info, "zoned: data %s needs raid-stripe-tree",
> btrfs_bg_type_to_raid_name(map->type));
> - return -EINVAL;
> + ret = -EINVAL;
> + goto out_free;
> }
>
> if (unlikely(cache->alloc_offset > cache->zone_capacity)) {
> @@ -1785,6 +1786,8 @@ int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache, bool new)
> btrfs_free_chunk_map(cache->physical_map);
> cache->physical_map = NULL;
> }
> +
> +out_free:
> bitmap_free(active);
> kfree(zone_info);
>

Wouldn't it make more sense to only set "ret = -EINVAL" and run the rest
of the functions cleanup? I.e. with your patch the chunk_map isn't freed
as well.