Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <CA+UBctC57Lx=8Eh6P51cVz+cyb02GE_B-dWnYhffWoc-nm7v6Q@mail.gmail.com>
 <9fff2b17-0b66-93a0-87aa-ca6479cb0663@intel.com>
In-Reply-To: <9fff2b17-0b66-93a0-87aa-ca6479cb0663@intel.com>
From:   Yu Hao <yhao016@ucr.edu>
Date:   Sun, 9 Jul 2023 17:55:22 -0700
Message-ID: <CA+UBctDVMXGcCi1ZVepNCGSZvhw4OR8fqWOOQjLkOQ6NXNAnJA@mail.gmail.com>
Subject: Re: [Intel-wired-lan] [PATCH] ethernet: e1000e: Fix possible uninit bug
To:     "Neftin, Sasha" <sasha.neftin@intel.com>
Cc:     jesse.brandeburg@intel.com, anthony.l.nguyen@intel.com,
        davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
        pabeni@redhat.com, intel-wired-lan@lists.osuosl.org,
        netdev@vger.kernel.org,
        linux-kernel <linux-kernel@vger.kernel.org>,
        "Ruinskiy, Dima" <dima.ruinskiy@intel.com>,
        "Edri, Michael" <michael.edri@intel.com>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

I think u16 phy_data =3D 0 would not hurt us.
Let me submit a patch which just initializes u16 phy_data =3D 0.

Yu Hao

On Wed, Jul 5, 2023 at 8:47=E2=80=AFAM Neftin, Sasha <sasha.neftin@intel.co=
m> wrote:
>
> On 7/5/2023 03:10, Yu Hao wrote:
> > The variable phy_data should be initialized in function e1e_rphy.
> > However, there is not return value check, which means there is a
> > possible uninit read later for the variable.
> >
> > Signed-off-by: Yu Hao <yhao016@ucr.edu>
> > ---
> >   drivers/net/ethernet/intel/e1000e/netdev.c | 5 ++++-
> >   1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c
> > b/drivers/net/ethernet/intel/e1000e/netdev.c
> > index 771a3c909c45..455af5e55cc6 100644
> > --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> > +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> > @@ -6910,8 +6910,11 @@ static int __e1000_resume(struct pci_dev *pdev)
> >      /* report the system wakeup cause from S3/S4 */
> >      if (adapter->flags2 & FLAG2_HAS_PHY_WAKEUP) {
> >          u16 phy_data;
> > +       s32 ret_val;
>
> why just not initialize u16 phy_data =3D 0? How did it hurt us? (legacy)
>
> >
> > -       e1e_rphy(&adapter->hw, BM_WUS, &phy_data);
> > +       ret_val =3D e1e_rphy(&adapter->hw, BM_WUS, &phy_data);
> > +       if (ret_val)
> > +           return ret_val;
> >          if (phy_data) {
> >              e_info("PHY Wakeup cause - %s\n",
> >                     phy_data & E1000_WUS_EX ? "Unicast Packet" :
>