netdev - Re: [PATCH bpf] xdp: Prevent overflow in devmap_hash cost calculation for 32-bit builds

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20191017115236.17895561@cakuba.netronome.com>
Date:   Thu, 17 Oct 2019 11:52:36 -0700
From:   Jakub Kicinski <jakub.kicinski@...ronome.com>
To:     Toke Høiland-Jørgensen <toke@...hat.com>
Cc:     daniel@...earbox.net, ast@...com, bpf@...r.kernel.org,
        netdev@...r.kernel.org,
        Tetsuo Handa <penguin-kernel@...ove.sakura.ne.jp>
Subject: Re: [PATCH bpf] xdp: Prevent overflow in devmap_hash cost
 calculation for 32-bit builds

On Thu, 17 Oct 2019 12:57:02 +0200, Toke Høiland-Jørgensen wrote:
> Tetsuo pointed out that without an explicit cast, the cost calculation for
> devmap_hash type maps could overflow on 32-bit builds. This adds the
> missing cast.
> 
> Fixes: 6f9d451ab1a3 ("xdp: Add devmap_hash map type for looking up devices by hashed index")
> Reported-by: Tetsuo Handa <penguin-kernel@...ove.sakura.ne.jp>
> Signed-off-by: Toke Høiland-Jørgensen <toke@...hat.com>
> ---
>  kernel/bpf/devmap.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
> index a0a1153da5ae..e34fac6022eb 100644
> --- a/kernel/bpf/devmap.c
> +++ b/kernel/bpf/devmap.c
> @@ -128,7 +128,7 @@ static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr)
>  
>  		if (!dtab->n_buckets) /* Overflow check */
>  			return -EINVAL;
> -		cost += sizeof(struct hlist_head) * dtab->n_buckets;
> +		cost += (u64) sizeof(struct hlist_head) * dtab->n_buckets;

array_size()?

>  	}
>  
>  	/* if map size is larger than memlock limit, reject it */