Re: [PATCH] netlink: Fix spectre v1 gadget in netlink_create()

[Josh Poimboeuf]

On Tue, Jul 31, 2018 at 09:13:16PM +0000, Jeremy Cline wrote:
> 'protocol' is a user-controlled value, so sanitize it after the bounds
> check to avoid using it for speculative out-of-bounds access to arrays
> indexed by it.
> 
> This addresses the following accesses detected with the help of smatch:
> 
> * net/netlink/af_netlink.c:654 __netlink_create() warn: potential
>   spectre issue 'nlk_cb_mutex_keys' [w]
> 
> * net/netlink/af_netlink.c:654 __netlink_create() warn: potential
>   spectre issue 'nlk_cb_mutex_key_strings' [w]
> 
> * net/netlink/af_netlink.c:685 netlink_create() warn: potential spectre
>   issue 'nl_table' [w] (local cap)
> 
> Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
> Signed-off-by: Jeremy Cline <jcline@xxxxxxxxxx>

Reviewed-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>

-- 
Josh