xfs
[Top] [All Lists]

Re: [PATCH] xfs: prevent range.len underflow in xfs_ioc_trim()

To: Lukas Czerner <lczerner@xxxxxxxxxx>, xfs@xxxxxxxxxxx
Subject: Re: [PATCH] xfs: prevent range.len underflow in xfs_ioc_trim()
From: Jeff Liu <jeff.liu@xxxxxxxxxx>
Date: Wed, 11 Dec 2013 21:10:48 +0800
Delivered-to: xfs@xxxxxxxxxxx
In-reply-to: <1386763525-18584-1-git-send-email-lczerner@xxxxxxxxxx>
References: <1386763525-18584-1-git-send-email-lczerner@xxxxxxxxxx>
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.1.0
Hi Lukas,

Thanks for the fix.  We have corrected this problem with the blow patch
which got merged intwo weeks ago. :)
[ commit f9fd013561 ]
xfs: don't perform discard if the given range length is less than block size

That is also discovered by generic/288 you contributed.

Thanks,
-Jeff

On 12/11 2013 20:05 PM, Lukas Czerner wrote:
> Currently when range.len is set to 0 it will underflow. Fix it by
> checking for this scenario and return EINVAL in case range.len is
> smaller than block size.
> 
> This was discovered by the xfstests generic/288 and with this patch
> the problem goes away.
> 
> Signed-off-by: Lukas Czerner <lczerner@xxxxxxxxxx>
> ---
>  fs/xfs/xfs_discard.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/xfs/xfs_discard.c b/fs/xfs/xfs_discard.c
> index 8367d6d..9029082 100644
> --- a/fs/xfs/xfs_discard.c
> +++ b/fs/xfs/xfs_discard.c
> @@ -180,7 +180,8 @@ xfs_ioc_trim(
>        * matter as trimming blocks is an advisory interface.
>        */
>       if (range.start >= XFS_FSB_TO_B(mp, mp->m_sb.sb_dblocks) ||
> -         range.minlen > XFS_FSB_TO_B(mp, XFS_ALLOC_AG_MAX_USABLE(mp)))
> +         range.minlen > XFS_FSB_TO_B(mp, XFS_ALLOC_AG_MAX_USABLE(mp)) ||
> +         range.len < XFS_FSB_TO_B(mp, 1))
>               return -XFS_ERROR(EINVAL);
>  
>       start = BTOBB(range.start);
> 

<Prev in Thread] Current Thread [Next in Thread>