Re: [PATCH] btrfs: fix invalid leaf access in btrfs_quota_enable() if ref key not found

[Sun YangKai <sunk67188@gmail.com>]

On 2026/2/5 01:28, fdmanana@kernel.org wrote:
> From: Filipe Manana <fdmanana@suse.com>
> 
> If btrfs_search_slot_for_read() returns 1, it means we did not find any
> key greather than or equals to the key we asked for, meaning we have
> reached the end of the tree and therefore the path is not valid. If
> this happens we need to break out of the loop and stop, instead of
> continuing and accessing an invalid path.
> 
> Fixes: 5223cc60b40a ("btrfs: drop the path before adding qgroup items when enabling qgroups")
> Signed-off-by: Filipe Manana <fdmanana@suse.com>
> ---
>   fs/btrfs/qgroup.c | 11 +++++++----
>   1 file changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
> index f53c313ab6e4..ea1806accdca 100644
> --- a/fs/btrfs/qgroup.c
> +++ b/fs/btrfs/qgroup.c
> @@ -1169,11 +1169,14 @@ int btrfs_quota_enable(struct btrfs_fs_info *fs_info,
>   			}
>   			if (ret > 0) {
>   				/*
> -				 * Shouldn't happen, but in case it does we
> -				 * don't need to do the btrfs_next_item, just
> -				 * continue.
> +				 * Shouldn't happen because the keu should still
keu -> key

Otherwise, looks good.

Reviewed-by: Sun YangKai <sunk67188@gmail.com>

Thanks,
Sun YangKai
> +				 * be there (return 0), but in case it does it
> +				 * means we have reached the end of the tree -
> +				 * there are no more leaves with items that have
> +				 * a key greater than or equals to @found_key,
> +				 * so just stop the search loop.
>   				 */
> -				continue;
> +				break;
>   			}
>   		}
>   		ret = btrfs_next_item(tree_root, path);