Re: [PATCH] ntfs : fix shift-out-of-bounds in ntfs_iget

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Aug 08, 2023 at 10:04:05AM +0530, Manas Ghandat wrote:
> Added a check to the compression_unit so that out of bound doesn't
> occur.
> 
> Signed-off-by: Manas Ghandat <ghandatmanas@gmail.com>
> Reported-by: syzbot+4768a8f039aa677897d0@syzkaller.appspotmail.com
> ---
>  fs/ntfs/inode.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/fs/ntfs/inode.c b/fs/ntfs/inode.c
> index 6c3f38d66579..2ee100a7df32 100644
> --- a/fs/ntfs/inode.c
> +++ b/fs/ntfs/inode.c
> @@ -1077,6 +1077,17 @@ static int ntfs_read_locked_inode(struct inode *vi)
>  					goto unm_err_out;
>  				}
>  				if (a->data.non_resident.compression_unit) {
> +					if(a->data.non_resident.compression_unit + 
> +						vol->cluster_size_bits > 32) {
> +							ntfs_error(vi->i_sb, "Found "
> +								"non-standard "
> +								"compression unit (%u).   "
> +								"Cannot handle this.",

Please do not split strings across lines.

And checkpatch will find other problems with this change as well, did
you run it before submitting it.

thanks,

greg k-h