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Date:   Wed, 5 Jul 2023 18:47:26 +0300
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Subject: Re: [Intel-wired-lan] [PATCH] ethernet: e1000e: Fix possible uninit
 bug
To:     Yu Hao <yhao016@ucr.edu>, <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>
References: <CA+UBctC57Lx=8Eh6P51cVz+cyb02GE_B-dWnYhffWoc-nm7v6Q@mail.gmail.com>
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From:   "Neftin, Sasha" <sasha.neftin@intel.com>
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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 = 0? How did it hurt us? (legacy)

> 
> -       e1e_rphy(&adapter->hw, BM_WUS, &phy_data);
> +       ret_val = 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" :