Re: [PATCH] ext4: fix buffer_head leak in ext4_ind_map_blocks() error path

[Zhang Yi]

On 10/9/2026 2:28 PM, guolingxing wrote:
> When ext4_ind_map_blocks() is called with EXT4_GET_BLOCKS_CREATE on
> a non-extent mapped inode of a filesystem with the bigalloc feature
> enabled, it fails with -EFSCORRUPTED via 'goto out'.  However, at
> this point ext4_get_branch() has already acquired buffer_head
> references for the chain of indirect blocks, which are stored in
> the stack variable 'chain'.  Since 'goto out' skips the cleanup
> loop that releases these references, they are leaked permanently
> (each failed allocation can leak up to 3 buffer_heads, and repeated
> allocation attempts keep pinning the corresponding pages in memory).
> 
> Jump to 'cleanup' instead, so that the chain of buffer_heads is
> properly released before the error is returned.
> 
> Signed-off-by: guolingxing <guolingxing@xxxxxxxxxx>

Looks good to me.

Reviewed-by: Zhang Yi <yi.zhang@xxxxxxxxxx>

> ---
>  fs/ext4/indirect.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c
> index 5aec759eed70..9f1f4e6c37a4 100644
> --- a/fs/ext4/indirect.c
> +++ b/fs/ext4/indirect.c
> @@ -603,7 +603,7 @@ int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
>  		EXT4_ERROR_INODE(inode, "Can't allocate blocks for "
>  				 "non-extent mapped inodes with bigalloc");
>  		err = -EFSCORRUPTED;
> -		goto out;
> +		goto cleanup;
>  	}
>  
>  	/* Set up for the direct block allocation */