[CRIU] [PATCH] mnt: Devpts options get corrupted on dump (v2)

[Andrew Vagin]

Acked-by: Andrew Vagin <avagin at parallels.com>

On Fri, May 30, 2014 at 06:47:35PM +0400, Pavel Emelyanov wrote:
> The memcpy() in devpts_dump() just overwrites part of them.
> Fix this and move the whole code into sub-routine for future.
> 
> v2: Fix off-by-one error spotted by Filipe.
> 
> Signed-off-by: Pavel Emelyanov <xemul at parallels.com>
> 
> ---
> 
>  mount.c | 35 +++++++++++++++++++++++------------
>  1 file changed, 23 insertions(+), 12 deletions(-)
> 
> diff --git a/mount.c b/mount.c
> index 1d960ae..d770e14 100644
> --- a/mount.c
> +++ b/mount.c
> @@ -559,15 +559,34 @@ out:
>  	return -1;
>  }
>  
> +static int attach_option(struct mount_info *pm, char *opt)
> +{
> +	char *buf;
> +	int len, olen;
> +
> +	len = strlen(pm->options);
> +	olen = strlen(opt);
> +	buf = xrealloc(pm->options, len + olen + 2);
> +	if (buf == NULL)
> +		return -1;
> +
> +	if (len && buf[len - 1] != ',') {
> +		buf[len] = ',';
> +		len++;
> +	}
> +
> +	memcpy(buf + len, opt, olen + 1);
> +	pm->options = buf;
> +
> +	return 0;
> +}
> +
>  /* Is it mounted w or w/o the newinstance option */
>  static int devpts_dump(struct mount_info *pm)
>  {
> -	static const char newinstance[] = ",newinstance";
>  	struct stat *host_st;
>  	struct stat st;
>  	int fdir;
> -	char *buf;
> -	int len;
>  
>  	host_st = kerndat_get_devpts_stat();
>  	if (host_st == NULL)
> @@ -588,15 +607,7 @@ static int devpts_dump(struct mount_info *pm)
>  	if (host_st->st_dev == st.st_dev)
>  		return 0;
>  
> -	len = strlen(pm->options);
> -	buf = xrealloc(pm->options, len + sizeof(newinstance));
> -	if (buf == NULL)
> -		return -1;
> -	memcpy(buf, newinstance, sizeof(newinstance));
> -
> -	pm->options = buf;
> -
> -	return 0;
> +	return attach_option(pm, "newinstance");
>  }
>  
>  static int tmpfs_dump(struct mount_info *pm)
> -- 
> 1.8.4.2
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