[llvm] r266248 - Start to add real error messages for malformed Mach-O files.
Sean Silva via llvm-commits
llvm-commits at lists.llvm.org
Thu Apr 14 20:25:46 PDT 2016
On Wed, Apr 13, 2016 at 2:17 PM, Kevin Enderby via llvm-commits <
llvm-commits at lists.llvm.org> wrote:
> Author: enderby
> Date: Wed Apr 13 16:17:58 2016
> New Revision: 266248
>
> URL: http://llvm.org/viewvc/llvm-project?rev=266248&view=rev
> Log:
> Start to add real error messages for malformed Mach-O files.
> And update the existing test cases in test/Object/macho-invalid.test
> to use llvm-objdump with the -macho option to produce these
> error messages and stop producing the generic "Invalid data
> was encountered while parsing the file" message.
>
> Working from the beginning of the file, if the mach header is too large for
> the size of the file and then if the load commands that follow extend past
> the end of the file these two errors now generate correct error messages.
>
> Both of these have existing test cases in test/Object/macho-invalid.test .
>
> But the first with macho-invalid-header it will never trigger the error
> message
> "mach header extends past the end of the file" using any of the llvm tools
> as
> they all use identify_magic() which rejects files with the correct magic
> number
> that are too small in size. So I tested this by hacking that code and
> seeing the
> error message down in parseHeader() really does happen. So in case there
> is ever code in llvm that directly calls createMachOObjectFile() this error
> message will be correctly produced.
>
> The second error message of "load commands extends past the end of the
> file"
> is triggered by a number of existing tests cases in
> test/Object/macho-invalid.test .
> Also other tests trigger different error messages now like "ilocalsym plus
> nlocalsym in LC_DYSYMTAB load command extends past the end of the
> symbol table".
>
> There are two existing test cases that still get the "Invalid data was
> encountered ..."
> error messages that I will tackle next. But they will involve a bit of
> pluming an
> Expect<...> up through the call stack and I want to do those as separate
> changes.
>
> FYI, for those test cases that were trying to test specific errors that
> now get
> different errors I’ll fix those in follow on changes and create new test
> cases
> for those so they test the error they were meant to test.
>
> Modified:
> llvm/trunk/lib/Object/MachOObjectFile.cpp
> llvm/trunk/test/Object/macho-invalid.test
>
> Modified: llvm/trunk/lib/Object/MachOObjectFile.cpp
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Object/MachOObjectFile.cpp?rev=266248&r1=266247&r2=266248&view=diff
>
> ==============================================================================
> --- llvm/trunk/lib/Object/MachOObjectFile.cpp (original)
> +++ llvm/trunk/lib/Object/MachOObjectFile.cpp Wed Apr 13 16:17:58 2016
> @@ -208,6 +208,11 @@ getNextLoadCommandInfo(const MachOObject
> template <typename T>
> static void parseHeader(const MachOObjectFile *Obj, T &Header,
> Error &Err) {
> + if (sizeof(T) > Obj->getData().size()) {
> + Err = malformedError(*Obj, "truncated or malformed object (the mach
> header "
> + "extends past the end of the file)");
> + return;
> + }
> if (auto HeaderOrErr = getStructOrErr<T>(Obj, getPtr(Obj, 0)))
> Header = *HeaderOrErr;
> else
> @@ -267,12 +272,22 @@ MachOObjectFile::MachOObjectFile(MemoryB
> DyldInfoLoadCmd(nullptr), UuidLoadCmd(nullptr),
> HasPageZeroSegment(false) {
> ErrorAsOutParameter ErrAsOutParam(Err);
> - if (is64Bit())
> + uint64_t big_size;
> + if (is64Bit()) {
> parseHeader(this, Header64, Err);
> - else
> + big_size = sizeof(MachO::mach_header_64);
> + } else {
> parseHeader(this, Header, Err);
> + big_size = sizeof(MachO::mach_header);
> + }
> if (Err)
> return;
> + big_size += getHeader().sizeofcmds;
> + if (getData().data() + big_size > getData().end()) {
> + Err = malformedError(getFileName(), "truncated or malformed object "
> + "(load commands extends past the end of the
> file)");
>
Did you intend "load command extends" or "load commands extend"?
-- Sean Silva
> + return;
> + }
>
> uint32_t LoadCommandCount = getHeader().ncmds;
> if (LoadCommandCount == 0)
>
> Modified: llvm/trunk/test/Object/macho-invalid.test
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Object/macho-invalid.test?rev=266248&r1=266247&r2=266248&view=diff
>
> ==============================================================================
> --- llvm/trunk/test/Object/macho-invalid.test (original)
> +++ llvm/trunk/test/Object/macho-invalid.test Wed Apr 13 16:17:58 2016
> @@ -9,11 +9,11 @@ RUN: not llvm-objdump -macho -private-he
> RUN: | FileCheck -check-prefix INCOMPLETE-LOADC %s
> INCOMPLETE-LOADC: truncated or malformed object (load command 0 extends
> past the end all load commands in the file)
>
> -RUN: not llvm-objdump -private-headers
> %p/Inputs/macho-invalid-too-small-load-command 2>&1 \
> +RUN: not llvm-objdump -macho -private-headers
> %p/Inputs/macho-invalid-too-small-load-command 2>&1 \
> RUN: | FileCheck -check-prefix SMALL-LOADC-SIZE %s
> -RUN: not llvm-objdump -private-headers
> %p/Inputs/macho64-invalid-too-small-load-command 2>&1 \
> +RUN: not llvm-objdump -macho -private-headers
> %p/Inputs/macho64-invalid-too-small-load-command 2>&1 \
> RUN: | FileCheck -check-prefix SMALL-LOADC-SIZE %s
> -SMALL-LOADC-SIZE: Mach-O load command with size < 8 bytes
> +SMALL-LOADC-SIZE: truncated or malformed object (load commands extends
> past the end of the file)
>
> RUN: not llvm-objdump -private-headers
> %p/Inputs/macho-invalid-too-small-segment-load-command 2>&1 \
> RUN: | FileCheck -check-prefix SMALL-SEGLOADC-SIZE %s
> @@ -27,13 +27,12 @@ RUN: not llvm-objdump -private-headers %
> RUN: | FileCheck -check-prefix TOO-MANY-SECTS %s
> TOO-MANY-SECTS: Mach-O segment load command contains too many sections
>
> -RUN: not llvm-objdump -t %p/Inputs/macho-invalid-bad-symbol-index 2>&1 \
> +RUN: not llvm-objdump -macho -t %p/Inputs/macho-invalid-bad-symbol-index
> 2>&1 \
> RUN: | FileCheck -check-prefix BAD-SYMBOL %s
> -BAD-SYMBOL: Invalid data was encountered while parsing the file.
> -RUN: llvm-objdump -t %p/Inputs/macho-valid-0-nsyms 2>&1 \
> +BAD-SYMBOL: truncated or malformed object (ilocalsym plus nlocalsym in
> LC_DYSYMTAB load command extends past the end of the symbol table)
> +RUN: llvm-objdump -macho -t %p/Inputs/macho-valid-0-nsyms 2>&1 \
> RUN: | FileCheck -check-prefix ZERO-NSYMS %s
> ZERO-NSYMS: SYMBOL TABLE
> -ZERO-NSYMS-NOT: Requested symbol index is out of range
>
> RUN: not llvm-objdump -t %p/Inputs/macho-invalid-symbol-name-past-eof
> 2>&1 \
> RUN: | FileCheck -check-prefix NAME-PAST-EOF %s
> @@ -58,9 +57,8 @@ RUN: not llvm-objdump -t %p/Inputs/macho
> RUN: | FileCheck -check-prefix
> INVALID-SECTION-IDX-SYMBOL-SEC-objdump %s
> INVALID-SECTION-IDX-SYMBOL-SEC-objdump: Invalid data was encountered
> while parsing the file.
>
> -RUN: not llvm-objdump -private-headers %p/Inputs/macho-invalid-header
> 2>&1 | FileCheck -check-prefix INVALID-HEADER %s
> -INVALID-HEADER: The file was not recognized as a valid object file.
> -NOT-INVALID-HEADER: Invalid data was encountered while parsing the file.
> +RUN: not llvm-objdump -macho -private-headers
> %p/Inputs/macho-invalid-header 2>&1 | FileCheck -check-prefix
> INVALID-HEADER %s
> +INVALID-HEADER: The file was not recognized as a valid object file
>
> -RUN: not llvm-objdump -private-headers
> %p/Inputs/macho64-invalid-incomplete-segment-load-command 2>&1 | FileCheck
> -check-prefix INCOMPLETE-SEGMENT-LOADC %s
> -INCOMPLETE-SEGMENT-LOADC: Invalid data was encountered while parsing the
> file
> +RUN: not llvm-objdump -macho -private-headers
> %p/Inputs/macho64-invalid-incomplete-segment-load-command 2>&1 | FileCheck
> -check-prefix INCOMPLETE-SEGMENT-LOADC %s
> +INCOMPLETE-SEGMENT-LOADC: truncated or malformed object (load commands
> extends past the end of the file)
>
>
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