Re: [PATCH] nilfs2: avoid overflowing segment numbers innilfs_ioctl_clean_segments()

[Ryusuke Konishi]

On Fri,  3 Feb 2012 10:26:07 -0500, Xi Wang wrote:
> nsegs is read from userspace.  Limit its value and avoid overflowing
> nsegs * sizeof(__u64) in the subsequent call to memdup_user().
> 
> This patch complements 481fe17e973fb97aa3edf17c69557afe88d8334f.
> 
> Signed-off-by: Xi Wang <xi.wang@xxxxxxxxx>
> Cc: Haogang Chen <haogangchen@xxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> ---
>  fs/nilfs2/ioctl.c |    2 ++
>  1 files changed, 2 insertions(+), 0 deletions(-)

Acked-by: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxxxxxx>


Thank you for posting this fix.

Andrew, could you send this uptream in this cycle ?

Ryusuke Konishi

> diff --git a/fs/nilfs2/ioctl.c b/fs/nilfs2/ioctl.c
> index 8866496..2a70fce 100644
> --- a/fs/nilfs2/ioctl.c
> +++ b/fs/nilfs2/ioctl.c
> @@ -603,6 +603,8 @@ static int nilfs_ioctl_clean_segments(struct inode *inode, struct file *filp,
>  	nsegs = argv[4].v_nmembs;
>  	if (argv[4].v_size != argsz[4])
>  		goto out;
> +	if (nsegs > UINT_MAX / sizeof(__u64))
> +		goto out;
>  
>  	/*
>  	 * argv[4] points to segment numbers this ioctl cleans.  We
> -- 
> 1.7.5.4
> 
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