Re: [PATCH] ntfs3: fix mapping pairs bounds check for alignment

[Konstantin Komarov <almaz.alexandrovich@paragon-software.com>]

On 8/5/26 08:45, Hongling Zeng wrote:

> In the UpdateMappingPairs action, the expansion check compares the
> unaligned new attribute size with the available record space. The new
> size is aligned to an 8-byte boundary before the mapping pairs are
> updated, so the check can underestimate the required space by up to
> seven bytes.
>
> Use the aligned size in the expansion check to ensure that the
> subsequent update cannot exceed the available record space.
>
> Fixes: b46acd6a6a62 ("fs/ntfs3: Add NTFS journal")
> Cc: stable@vger.kernel.org
> Signed-off-by: Hongling Zeng <zenghongling@kylinos.cn>
> ---
>   fs/ntfs3/fslog.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/fs/ntfs3/fslog.c b/fs/ntfs3/fslog.c
> index cc24c23e4db9..3440212ecb12 100644
> --- a/fs/ntfs3/fslog.c
> +++ b/fs/ntfs3/fslog.c
> @@ -3388,7 +3388,8 @@ static int do_action(struct ntfs_log *log, struct OPEN_ATTR_ENRTY *oe,
>   
>   		if (!check_if_attr(rec, lrh) || !attr->non_res ||
>   		    aoff < le16_to_cpu(attr->nres.run_off) || aoff > asize ||
> -		    (nsize > asize && nsize - asize > record_size - used)) {
> +		    (nsize > asize &&
> +		     ALIGN(nsize, 8) - asize > record_size - used)) {
>   			goto dirty_vol;
>   		}
>   

Hello,

Your patch is applied, thanks.

Regards,
Konstantin