Re: [PATCH 6.12.y 1/4] fs/ntfs3: Add more checks in mi_enum_attr (part 2)

[Greg KH <greg@kroah.com>]

On Wed, Sep 09, 2026 at 09:26:07PM -0400, Sasha Levin wrote:
> From: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
> 
> [ Upstream commit a8f659ce14f8f734894227ba2c5ca78c8451501e ]
> 
> Add offset check before access to attr->non_res field as mentioned in [1].
> 
> [1] https://lore.kernel.org/ntfs3/20241010110005.42792-1-llfamsec@gmail.com/
> 
> Suggested-by: lei lu <llfamsec@gmail.com>
> Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
> Stable-dep-of: 7c4841e2a627 ("fs/ntfs3: fix slab-out-of-bounds write in ni_create_attr_list()")
> Signed-off-by: Sasha Levin <sashal@kernel.org>
> ---
>  fs/ntfs3/record.c | 16 +++++++++++++---
>  1 file changed, 13 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/ntfs3/record.c b/fs/ntfs3/record.c
> index f810f0419d25e..61d53d39f3b9f 100644
> --- a/fs/ntfs3/record.c
> +++ b/fs/ntfs3/record.c
> @@ -212,7 +212,7 @@ struct ATTRIB *mi_enum_attr(struct mft_inode *mi, struct ATTRIB *attr)
>  			return NULL;
>  
>  		if (off >= used || off < MFTRECORD_FIXUP_OFFSET_1 ||
> -		    !IS_ALIGNED(off, 4)) {
> +		    !IS_ALIGNED(off, 8)) {
>  			return NULL;
>  		}
>  
> @@ -236,8 +236,11 @@ struct ATTRIB *mi_enum_attr(struct mft_inode *mi, struct ATTRIB *attr)
>  		off += asize;
>  	}
>  
> -	/* Can we use the first field (attr->type). */
> -	/* NOTE: this code also checks attr->size availability. */
> +	/*
> +	 * Can we use the first fields:
> +	 * attr->type,
> +	 * attr->size
> +	 */
>  	if (off + 8 > used) {
>  		static_assert(ALIGN(sizeof(enum ATTR_TYPE), 8) == 8);
>  		return NULL;
> @@ -259,10 +262,17 @@ struct ATTRIB *mi_enum_attr(struct mft_inode *mi, struct ATTRIB *attr)
>  
>  	asize = le32_to_cpu(attr->size);
>  
> +	if (!IS_ALIGNED(asize, 8))
> +		return NULL;
> +
>  	/* Check overflow and boundary. */
>  	if (off + asize < off || off + asize > used)
>  		return NULL;
>  
> +	/* Can we use the field attr->non_res. */
> +	if (off + 9 > used)
> +		return NULL;
> +
>  	/* Check size of attribute. */
>  	if (!attr->non_res) {
>  		/* Check resident fields. */
> -- 
> 2.53.0
> 
> 

did not apply