netdev - Re: [PATCH net-next 1/4] net: Add SRIOV VGT+ support

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: <20170828155217.GA8399@bistromath.localdomain>
Date:   Mon, 28 Aug 2017 17:52:17 +0200
From:   Sabrina Dubroca <sd@...asysnail.net>
To:     Saeed Mahameed <saeedm@...lanox.com>
Cc:     "David S. Miller" <davem@...emloft.net>, netdev@...r.kernel.org,
        Eugenia Emantayev <eugenia@...lanox.com>,
        Mohamad Haj Yahia <mohamad@...lanox.com>,
        Hannes Frederic Sowa <hannes@...essinduktion.org>
Subject: Re: [PATCH net-next 1/4] net: Add SRIOV VGT+ support

2017-08-27, 14:06:15 +0300, Saeed Mahameed wrote:
[...]
> +#define VF_VLAN_BITMAP	DIV_ROUND_UP(VF_VLAN_N_VID, sizeof(__u64) * BITS_PER_BYTE)
> +struct ifla_vf_vlan_trunk {
> +	__u32 vf;
> +	__u64 allowed_vlans_8021q_bm[VF_VLAN_BITMAP];
> +	__u64 allowed_vlans_8021ad_bm[VF_VLAN_BITMAP];
> +};

This is huge (1032B). And you put one of these in the netlink message
for each VF.  This means that with 51 VF (at least in my environment,
where each VF takes 1296B), you're going to overflow the u16 size of a
single attribute (IFLA_VFINFO_LIST), and you cannot dump the device
anymore. I'm afraid this is going to break existing setups.

-- 
Sabrina