On 10/10/17 04:46, Wu, Hao A wrote: > Some comments below. Given that a new version of this patch looks necessary, I'd like to request an improved subject line / commit message:
(1) For the subject prefix, we should use: SecurityPkg/SecureBootConfigDxe: ... (2) It looks like the issue (= NULL pointer dereferencing) can occur when the platform does not install the appropriate strings into the HII database. All these strings are apparently identified by STR_SIGNATURE_* tokens. So how about the following subject: SecurityPkg/SecureBootConfigDxe: cope with lack of STR_SIGNATURE_* tokens (This subject is 73 characters long.) (3) Can we please capture some details about the issue in the commit message? Namely, I thought it was not possible for these tokens to be missing. Apparently they *can* be missing. Can we describe, briefly, how and when that happens, in practice? Thanks! Laszlo >> -----Original Message----- >> From: Chen, Chen A >> Sent: Tuesday, October 10, 2017 10:08 AM >> To: [email protected] >> Cc: Chen, Chen A; Zhang, Chao B; Wu, Hao A >> Subject: [PATCH] SecurityPkg/SecureBootConfigImpl.c: Fix the potential NULL >> dereference. >> >> Cc: Zhang Chao <[email protected]> >> Cc: Wu Hao <[email protected]> >> Contributed-under: TianoCore Contribution Agreement 1.0 >> Signed-off-by: Chen A Chen <[email protected]> >> --- >> .../SecureBootConfigDxe/SecureBootConfigImpl.c | 80 +++++++++++++++---- >> --- >> 1 file changed, 57 insertions(+), 23 deletions(-) >> >> diff --git >> a/SecurityPkg/VariableAuthenticated/SecureBootConfigDxe/SecureBootConfigI >> mpl.c >> b/SecurityPkg/VariableAuthenticated/SecureBootConfigDxe/SecureBootConfigI >> mpl.c >> index 3e03be9738..457e020ece 100644 >> --- >> a/SecurityPkg/VariableAuthenticated/SecureBootConfigDxe/SecureBootConfigI >> mpl.c >> +++ >> b/SecurityPkg/VariableAuthenticated/SecureBootConfigDxe/SecureBootConfigI >> mpl.c >> @@ -3579,7 +3579,9 @@ LoadSignatureList ( >> ) >> { >> EFI_STATUS Status; >> - EFI_STRING_ID ListType; >> + EFI_STRING EfiStringTemp1; >> + EFI_STRING EfiStringTemp2; >> + EFI_STRING_ID ListType;; > > An extra ';' is used here. > >> EFI_SIGNATURE_LIST *ListWalker; >> EFI_IFR_GUID_LABEL *StartLabel; >> EFI_IFR_GUID_LABEL *EndLabel; >> @@ -3599,6 +3601,8 @@ LoadSignatureList ( >> CHAR16 *HelpBuffer; >> >> Status = EFI_SUCCESS; >> + EfiStringTemp1 = NULL; >> + EfiStringTemp2 = NULL; >> StartOpCodeHandle = NULL; >> EndOpCodeHandle = NULL; >> StartGotoHandle = NULL; >> @@ -3755,17 +3759,19 @@ LoadSignatureList ( >> ListType = STRING_TOKEN (STR_LIST_TYPE_UNKNOWN); >> } >> >> - UnicodeSPrint (NameBuffer, >> - 100, >> - HiiGetString (PrivateData->HiiHandle, STRING_TOKEN >> (STR_SIGNATURE_LIST_NAME_FORMAT), NULL), >> - Index + 1 >> - ); >> - UnicodeSPrint (HelpBuffer, >> - 100, >> - HiiGetString (PrivateData->HiiHandle, STRING_TOKEN >> (STR_SIGNATURE_LIST_HELP_FORMAT), NULL), >> - HiiGetString (PrivateData->HiiHandle, ListType, NULL), >> - SIGNATURE_DATA_COUNTS (ListWalker) >> - ); >> + EfiStringTemp1 = HiiGetString (PrivateData->HiiHandle, STRING_TOKEN >> (STR_SIGNATURE_LIST_NAME_FORMAT), NULL); >> + if (EfiStringTemp1 == NULL) { >> + goto ON_EXIT; >> + } >> + UnicodeSPrint (NameBuffer, 100, EfiStringTemp1, Index + 1); >> + EfiStringTemp1 = NULL; > > Before setting 'EfiStringTemp1' to NULL, I think the returned string from > HiiGetString() should be freed first. There are many similar cases in the > codes. > > Also, could you help to replace the usages of '100' like: > > * VariableName = AllocateZeroPool (100); > * NameBuffer = AllocateZeroPool (100); > * UnicodeSPrint (NameBuffer, 100, EfiStringTemp1, Index + 1); > ... > > with a macro? It will be helpful for maintaining the codes. > > And how about declaring string buffers like 'VariableName', 'NameBuffer' > as arrays instead of allocating them on the heap? > >> + >> + EfiStringTemp1 = HiiGetString (PrivateData->HiiHandle, STRING_TOKEN >> (STR_SIGNATURE_LIST_HELP_FORMAT), NULL); >> + EfiStringTemp2 = HiiGetString (PrivateData->HiiHandle, ListType, NULL); >> + if (EfiStringTemp1 == NULL || EfiStringTemp2 == NULL) { >> + goto ON_EXIT; >> + } >> + UnicodeSPrint (HelpBuffer, 100, EfiStringTemp1, EfiStringTemp2, >> SIGNATURE_DATA_COUNTS (ListWalker)); >> >> HiiCreateGotoOpCode ( >> StartOpCodeHandle, >> @@ -3953,6 +3959,8 @@ FormatHelpInfo ( >> { >> EFI_STATUS Status; >> EFI_TIME *Time; >> + EFI_STRING EfiStringTemp1; >> + EFI_STRING EfiStringTemp2; >> EFI_STRING_ID ListTypeId; >> UINTN DataSize; >> UINTN HelpInfoIndex; >> @@ -3964,6 +3972,8 @@ FormatHelpInfo ( >> BOOLEAN IsCert; >> >> Status = EFI_SUCCESS; >> + EfiStringTemp1 = NULL; >> + EfiStringTemp2 = NULL; >> Time = NULL; >> HelpInfoIndex = 0; >> GuidString = NULL; >> @@ -4016,6 +4026,10 @@ FormatHelpInfo ( >> goto ON_EXIT; >> } >> >> + EfiStringTemp1 = HiiGetString (PrivateData->HiiHandle, STRING_TOKEN >> (STR_SIGNATURE_DATA_HELP_FORMAT_GUID), NULL); >> + if (EfiStringTemp1 == NULL) { >> + goto ON_EXIT; >> + } >> // >> // Format GUID part. >> // >> @@ -4023,20 +4037,29 @@ FormatHelpInfo ( >> HelpInfoIndex += UnicodeSPrint ( >> &HelpInfoString[HelpInfoIndex], >> TotalSize - sizeof(CHAR16) * HelpInfoIndex, >> - HiiGetString (PrivateData->HiiHandle, STRING_TOKEN >> (STR_SIGNATURE_DATA_HELP_FORMAT_GUID), NULL), >> + EfiStringTemp1, >> GuidString >> ); >> + EfiStringTemp1 = NULL; >> >> + EfiStringTemp2 = HiiGetString (PrivateData->HiiHandle, ListTypeId, NULL); >> + if (EfiStringTemp2 == NULL) { >> + goto ON_EXIT; >> + } >> // >> // Format content part, it depends on the type of signature list, hash >> value or >> CN. >> // >> if (IsCert) { >> GetCommonNameFromX509 (ListEntry, DataEntry, &DataString); >> + EfiStringTemp1 = HiiGetString (PrivateData->HiiHandle, STRING_TOKEN >> (STR_SIGNATURE_DATA_HELP_FORMAT_CN), NULL); >> + if (EfiStringTemp1 == NULL) { >> + goto ON_EXIT; >> + } >> HelpInfoIndex += UnicodeSPrint( >> &HelpInfoString[HelpInfoIndex], >> TotalSize - sizeof(CHAR16) * HelpInfoIndex, >> - HiiGetString (PrivateData->HiiHandle, STRING_TOKEN >> (STR_SIGNATURE_DATA_HELP_FORMAT_CN), NULL), >> - HiiGetString (PrivateData->HiiHandle, ListTypeId, >> NULL), >> + EfiStringTemp1, >> + EfiStringTemp2, >> DataSize, >> DataString >> ); >> @@ -4045,15 +4068,20 @@ FormatHelpInfo ( >> // Format hash value for each signature data entry. >> // >> ParseHashValue (ListEntry, DataEntry, &DataString); >> + EfiStringTemp1 = HiiGetString (PrivateData->HiiHandle, STRING_TOKEN >> (STR_SIGNATURE_DATA_HELP_FORMAT_HASH), NULL); >> + if (EfiStringTemp1 == NULL) { >> + goto ON_EXIT; >> + } >> HelpInfoIndex += UnicodeSPrint ( >> &HelpInfoString[HelpInfoIndex], >> TotalSize - sizeof(CHAR16) * HelpInfoIndex, >> - HiiGetString (PrivateData->HiiHandle, STRING_TOKEN >> (STR_SIGNATURE_DATA_HELP_FORMAT_HASH), NULL), >> - HiiGetString (PrivateData->HiiHandle, ListTypeId, >> NULL), >> + EfiStringTemp1, >> + EfiStringTemp2, >> DataSize, >> DataString >> ); >> } >> + EfiStringTemp1 = NULL; >> >> // >> // Format revocation time part. >> @@ -4077,10 +4105,14 @@ FormatHelpInfo ( >> Time->Second >> ); >> >> + EfiStringTemp1 = HiiGetString (PrivateData->HiiHandle, STRING_TOKEN >> (STR_SIGNATURE_DATA_HELP_FORMAT_TIME), NULL); >> + if (EfiStringTemp1 == NULL) { >> + goto ON_EXIT; >> + } >> UnicodeSPrint ( >> &HelpInfoString[HelpInfoIndex], >> TotalSize - sizeof (CHAR16) * HelpInfoIndex, >> - HiiGetString (PrivateData->HiiHandle, STRING_TOKEN >> (STR_SIGNATURE_DATA_HELP_FORMAT_TIME), NULL), >> + EfiStringTemp1, >> TimeString >> ); >> } >> @@ -4122,6 +4154,7 @@ LoadSignatureData ( >> EFI_SIGNATURE_DATA *DataWalker; >> EFI_IFR_GUID_LABEL *StartLabel; >> EFI_IFR_GUID_LABEL *EndLabel; >> + EFI_STRING EfiString; >> EFI_STRING_ID HelpStringId; >> VOID *StartOpCodeHandle; >> VOID *EndOpCodeHandle; >> @@ -4133,6 +4166,7 @@ LoadSignatureData ( >> CHAR16 *NameBuffer; >> >> Status = EFI_SUCCESS; >> + EfiString = NULL; >> StartOpCodeHandle = NULL; >> EndOpCodeHandle = NULL; >> Index = 0; >> @@ -4229,15 +4263,15 @@ LoadSignatureData ( >> } >> >> DataWalker = (EFI_SIGNATURE_DATA *)((UINT8 *)ListWalker + >> sizeof(EFI_SIGNATURE_LIST) + ListWalker->SignatureHeaderSize); >> + EfiString = HiiGetString (PrivateData->HiiHandle, STRING_TOKEN >> (STR_SIGNATURE_DATA_NAME_FORMAT), NULL); >> + if (EfiString == NULL) { >> + goto ON_EXIT; >> + } >> for (Index = 0; Index < SIGNATURE_DATA_COUNTS(ListWalker); Index = Index >> + 1) { >> // >> // Format name buffer. >> // >> - UnicodeSPrint (NameBuffer, >> - 100, >> - HiiGetString (PrivateData->HiiHandle, STRING_TOKEN >> (STR_SIGNATURE_DATA_NAME_FORMAT), NULL), >> - Index + 1 >> - ); >> + UnicodeSPrint (NameBuffer, 100, EfiString, Index + 1); >> >> // >> // Format help info buffer. >> -- >> 2.13.2.windows.1 > > _______________________________________________ > edk2-devel mailing list > [email protected] > https://lists.01.org/mailman/listinfo/edk2-devel > _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
