Re: [PATCH][net-next] ipv6: fix incorrect bitwise operator used on rt6i_flags

[Martin KaFai Lau]

On Tue, Oct 10, 2017 at 05:55:27PM +0000, Colin King wrote:
> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> 
> The use of the | operator always leads to true on the expression
> (rt->rt6i_flags | RTF_CACHE) which looks rather suspect to me. I
> believe this is fixed by using & instead to just check the
> RTF_CACHE entry bit.
Good catch. LGTM. If rt does not have RTF_CACHE set, it should not be in the
exception table.

Acked-by: Martin KaFai Lau <kafai@xxxxxx>

> 
> Detected by CoverityScan, CID#1457747 ("Wrong operator used")
> 
> Fixes: 35732d01fe31 ("ipv6: introduce a hash table to store dst cache")
> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> ---
>  net/ipv6/route.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/net/ipv6/route.c b/net/ipv6/route.c
> index 6db1541eaa7b..0556d1ee189c 100644
> --- a/net/ipv6/route.c
> +++ b/net/ipv6/route.c
> @@ -1425,7 +1425,7 @@ int rt6_remove_exception_rt(struct rt6_info *rt)
>  	int err;
>  
>  	if (!from ||
> -	    !(rt->rt6i_flags | RTF_CACHE))
> +	    !(rt->rt6i_flags & RTF_CACHE))
>  		return -EINVAL;
>  
>  	if (!rcu_access_pointer(from->rt6i_exception_bucket))
> -- 
> 2.14.1
>