netdev - Re: [PATCH v2 2/2] r8169: Avoid pointer aliasing

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]

Date:   Tue, 05 Feb 2019 10:42:54 -0800
From:   Joe Perches <joe@...ches.com>
To:     David Miller <davem@...emloft.net>, thierry.reding@...il.com
Cc:     hkallweit1@...il.com, andrew@...n.ch, nic_swsd@...ltek.com,
        netdev@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 2/2] r8169: Avoid pointer aliasing

On Mon, 2019-02-04 at 19:20 -0800, David Miller wrote:
> From: Thierry Reding <thierry.reding@...il.com>
> Date: Mon,  4 Feb 2019 17:42:13 +0100
> 
> > @@ -7316,7 +7325,7 @@ static int rtl_get_ether_clk(struct rtl8169_private *tp)
> >  static int rtl_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
> >  {
> >       const struct rtl_cfg_info *cfg = rtl_cfg_infos + ent->driver_data;
> > -     u8 mac_addr[ETH_ALEN] __aligned(4) = {};
> > +     u8 mac_addr[ETH_ALEN] = {};
> >       struct rtl8169_private *tp;
> 
> I agree with Heiner, you have to provide at least 2 byte alignment for this
> buffer due to the reasons he stated.

It's declared after a pointer so it is already is 2 byte aligned.

A lot of drivers wouldn't work otherwise.