Re: [PATCH v3] ntfs : fix shift-out-of-bounds in ntfs_iget

[Greg KH <gregkh@linuxfoundation.org>]

On Thu, Aug 10, 2023 at 09:43:08PM +0530, Manas Ghandat wrote:
> Added a check to the compression_unit so that out of bound doesn't occur.

This probably needs more text to describe what is happening.


> 
> Signed-off-by: Manas Ghandat <ghandatmanas@gmail.com>
> Reported-by: syzbot+4768a8f039aa677897d0@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=4768a8f039aa677897d0

What commit id does this fix?  Should it go to stable kernels?


> ---
> V2 -> V3: Fix patching issue.
> V1 -> V2: Cleaned up coding style.
> 
>  fs/ntfs/inode.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/fs/ntfs/inode.c b/fs/ntfs/inode.c
> index 6c3f38d66579..a657322874ed 100644
> --- a/fs/ntfs/inode.c
> +++ b/fs/ntfs/inode.c
> @@ -1077,6 +1077,15 @@ 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) {

Should be indented a bit left, right?

> +						ntfs_error(vi->i_sb,
> +							"Found non-standard compression unit (%u).   Cannot handle this.",

Why all the extra ' ' characters?

thanks,

greg k-h