Hi, Jiaxin In the line you are modifying the UDNI is always not started. You should move the Nii->Id to the line after PxeStart(), not to check it here.
BestRegards Fu Siyuan > -----Original Message----- > From: Wu, Jiaxin > Sent: Thursday, December 21, 2017 3:13 PM > To: edk2-devel@lists.01.org > Cc: Wang, Fan <fan.w...@intel.com>; Ye, Ting <ting...@intel.com>; Fu, > Siyuan <siyuan...@intel.com>; Wu, Jiaxin <jiaxin...@intel.com> > Subject: [Patch] MdeModulePkg/SnpDxe: Check the value of Nii->Id before > use it directly. > > Nii->Id is the address of the first byte of the identifying structure > for this network interface. This is only valid when the network interface > is started. When the network interface is not started, this field is set > to zero. So, we should check the value of Nii->Id before use it directly. > > Cc: Wang Fan <fan.w...@intel.com> > Cc: Ye Ting <ting...@intel.com> > Cc: Fu Siyuan <siyuan...@intel.com> > Contributed-under: TianoCore Contribution Agreement 1.0 > Signed-off-by: Wu Jiaxin <jiaxin...@intel.com> > --- > MdeModulePkg/Universal/Network/SnpDxe/Snp.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/MdeModulePkg/Universal/Network/SnpDxe/Snp.c > b/MdeModulePkg/Universal/Network/SnpDxe/Snp.c > index 9f61aee..f0257a2 100644 > --- a/MdeModulePkg/Universal/Network/SnpDxe/Snp.c > +++ b/MdeModulePkg/Universal/Network/SnpDxe/Snp.c > @@ -1,9 +1,9 @@ > /** @file > Implementation of driver entry point and driver binding protocol. > > -Copyright (c) 2004 - 2016, Intel Corporation. All rights reserved.<BR> > +Copyright (c) 2004 - 2017, Intel Corporation. All rights reserved.<BR> > This program and the accompanying materials are licensed > and made available under the terms and conditions of the BSD License > which > accompanies this distribution. The full text of the license may be found > at > http://opensource.org/licenses/bsd-license.php > > @@ -333,10 +333,15 @@ SimpleNetworkDriverStart ( > return Status; > } > > DEBUG ((EFI_D_INFO, "Start(): UNDI3.1 found\n")); > > + if (Nii->Id == 0) { > + DEBUG ((EFI_D_NET, "\nUNDI is not started.\n")); > + goto NiiError; > + } > + > Pxe = (PXE_UNDI *) (UINTN) (Nii->Id); > > if (Calc8BitCksum (Pxe, Pxe->hw.Len) != 0) { > DEBUG ((EFI_D_NET, "\n!PXE checksum is not correct.\n")); > goto NiiError; > -- > 1.9.5.msysgit.1 _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel
