Re: [PATCH v1 1/1] ShellPkg/Ifconfig6: Address ASSERT because of a missing NULL check

["Zhang, Lubo" <lubo.zhang@intel.com>]

Reviewed-by: Zhang Lubo <lubo.zhang@intel.com>

> -----Original Message-----
> From: hegdenag [mailto:nagaraj-p.hegde@hpe.com]
> Sent: Thursday, January 12, 2017 11:40 AM
> To: edk2-devel@lists.01.org
> Cc: Wu, Jiaxin <jiaxin.wu@intel.com>; Carsey, Jaben <jaben.carsey@intel.com>;
> Ni, Ruiyu <ruiyu.ni@intel.com>; Zhang, Lubo <lubo.zhang@intel.com>; sriram-
> s@hpe.com
> Subject: [PATCH v1 1/1] ShellPkg/Ifconfig6: Address ASSERT because of a
> missing NULL check
> 
> When we issue 'ifconfig6 -s <interface> auto' system hangs with an ASSERT in
> StrLen. in IfConfig6SetInterfaceInfo, for 'auto' case we added checks to rule out
> the invalid inputs like 'host', 'gw'
> and 'dns'. To parse through this, we do a VarArg = VarArg->Next but we dont
> check new VarArg before calling StrCmp. Fix with a check in this patch.
> 
> Contributed-under: TianoCore Contribution Agreement 1.0
> Signed-off-by: Hegde Nagaraj P <nagaraj-p.hegde@hpe.com>
> ---
>  ShellPkg/Library/UefiShellNetwork2CommandsLib/Ifconfig6.c | 27
> ++++++++++----------
>  1 file changed, 14 insertions(+), 13 deletions(-)
> 
> diff --git a/ShellPkg/Library/UefiShellNetwork2CommandsLib/Ifconfig6.c
> b/ShellPkg/Library/UefiShellNetwork2CommandsLib/Ifconfig6.c
> index d71688e..72aaee4 100644
> --- a/ShellPkg/Library/UefiShellNetwork2CommandsLib/Ifconfig6.c
> +++ b/ShellPkg/Library/UefiShellNetwork2CommandsLib/Ifconfig6.c
> @@ -1317,20 +1317,21 @@ IfConfig6SetInterfaceInfo (
> 
>        VarArg= VarArg->Next;
> 
> -      if (StrCmp (VarArg->Arg, L"host") == 0) {
> -        ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN
> (STR_IFCONFIG6_ERR_INVALID_IP_CONFIG), gShellNetwork2HiiHandle, Status);
> -        ShellStatus = SHELL_INVALID_PARAMETER;
> -        goto ON_EXIT;
> -      } else if (StrCmp (VarArg->Arg, L"gw") == 0) {
> -        ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN
> (STR_IFCONFIG6_ERR_INVALID_GW_CONFIG), gShellNetwork2HiiHandle,
> Status);
> -        ShellStatus = SHELL_INVALID_PARAMETER;
> -        goto ON_EXIT;
> -      } else if (StrCmp (VarArg->Arg, L"dns") == 0) {
> -        ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN
> (STR_IFCONFIG6_ERR_INVALID_DNS_CONFIG), gShellNetwork2HiiHandle,
> Status);
> -        ShellStatus = SHELL_INVALID_PARAMETER;
> -        goto ON_EXIT;
> +      if (VarArg != NULL) {
> +        if (StrCmp (VarArg->Arg, L"host") == 0) {
> +          ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN
> (STR_IFCONFIG6_ERR_INVALID_IP_CONFIG), gShellNetwork2HiiHandle, Status);
> +          ShellStatus = SHELL_INVALID_PARAMETER;
> +          goto ON_EXIT;
> +        } else if (StrCmp (VarArg->Arg, L"gw") == 0) {
> +          ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN
> (STR_IFCONFIG6_ERR_INVALID_GW_CONFIG), gShellNetwork2HiiHandle,
> Status);
> +          ShellStatus = SHELL_INVALID_PARAMETER;
> +          goto ON_EXIT;
> +        } else if (StrCmp (VarArg->Arg, L"dns") == 0) {
> +          ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN
> (STR_IFCONFIG6_ERR_INVALID_DNS_CONFIG), gShellNetwork2HiiHandle,
> Status);
> +          ShellStatus = SHELL_INVALID_PARAMETER;
> +          goto ON_EXIT;
> +        }
>        }
> -
>      } else if (StrCmp (VarArg->Arg, L"man") == 0) {
>        //
>        // Set manual config policy.
> --
> 2.8.3.windows.1