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Date:   Mon, 10 Jul 2023 10:55:35 +0300
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Subject: Re: [Intel-wired-lan] [PATCH] ethernet: e1000e: Fix possible uninit
 bug
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To:     Yu Hao <yhao016@ucr.edu>
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>
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From:   "Neftin, Sasha" <sasha.neftin@intel.com>
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On 7/10/2023 03:55, Yu Hao wrote:
> I think u16 phy_data = 0 would not hurt us.
> Let me submit a patch which just initializes u16 phy_data = 0.
Good.
> 
> Yu Hao
> 
> On Wed, Jul 5, 2023 at 8:47 AM Neftin, Sasha <sasha.neftin@intel.com> 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 = 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" :
>>