[CRIU] [PATCH 3/9] read_ns_sys_file(): don't overrun buf

[Andrew Vagin]

On Wed, Oct 07, 2015 at 02:44:18AM -0700, Kir Kolyshkin wrote:
> This is a classical off-by-one error. If sizeof(buf) is 512,
> the last element is buf[511] but not buf[512].
> 
> Note that if read() returns 0, we return 0 but buf stays
> uninitialized.
> 
> Reported by Coverity, CID 114623.

Acked-by: Andrew Vagin <avagin at odin.com>
> 
> Signed-off-by: Kir Kolyshkin <kir at openvz.org>
> ---
>  net.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/net.c b/net.c
> index 96f2fcc..08ef865 100644
> --- a/net.c
> +++ b/net.c
> @@ -45,8 +45,8 @@ int read_ns_sys_file(char *path, char *buf, int len)
>  	rlen = read(fd, buf, len);
>  	close(fd);
>  
> -	if (rlen >= 0)
> -		buf[rlen] = '\0';
> +	if (rlen > 0)
> +		buf[rlen - 1] = '\0';
>  
>  	return rlen;
>  }
> -- 
> 2.4.3
> 
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