Re: [PATCH] ntfs: Use return instead of goto in ntfs_mapping_pairs_decompress()

[Hyunchul Lee <hyc.lee@gmail.com>]

On Tue, Apr 28, 2026 at 03:21:38PM -0400, Nathan Chancellor wrote:
> Clang warns (or errors with CONFIG_WERROR=y / W=e):
> 
>   fs/ntfs/runlist.c:755:6: error: variable 'rl' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized]
>     755 |         if (overflows_type(lowest_vcn, vcn)) {
>         |             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>   ...
>   fs/ntfs/runlist.c:971:9: note: uninitialized use occurs here
>     971 |         kvfree(rl);
>         |                ^~
>   ...
> 
> rl has not been allocated at this point so the 'goto err_out' should
> really just be a return of the error pointer -EIO.
> 
> Fixes: cad7c6f0a514 ("ntfs: fix VCN overflow in ntfs_mapping_pairs_decompress()")
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>

Thank you for this patch.

Reviewed-by: Hyunchul Lee <hyc.lee@gmail.com>

> ---
>  fs/ntfs/runlist.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/ntfs/runlist.c b/fs/ntfs/runlist.c
> index be6ca3d374bb..da21dbeaaf66 100644
> --- a/fs/ntfs/runlist.c
> +++ b/fs/ntfs/runlist.c
> @@ -754,7 +754,7 @@ struct runlist_element *ntfs_mapping_pairs_decompress(const struct ntfs_volume *
>  	/* Validate lowest_vcn from on-disk metadata to ensure it is sane. */
>  	if (overflows_type(lowest_vcn, vcn)) {
>  		ntfs_error(vol->sb, "Invalid lowest_vcn in mapping pairs.");
> -		goto err_out;
> +		return ERR_PTR(-EIO);
>  	}
>  	/* Start at vcn = lowest_vcn and lcn 0. */
>  	vcn = lowest_vcn;
> 
> ---
> base-commit: d986ba0329dcca102e227995371135c9bbcefb6b
> change-id: 20260428-ntfs-fix-sometimes-uninit-rl-cfe3c6a9c34e
> 
> Best regards,
> --  
> Nathan Chancellor <nathan@kernel.org>
> 

-- 
Thanks,
Hyunchul