[PATCH] D62898: [llvm-objcopy] - Emit error and don't crash if program header reaches past end of file.

[George Rimar via Phabricator via llvm-commits]

grimar updated this revision to Diff 203128.
grimar marked 4 inline comments as done.
grimar added a comment.

- Addressed review comments.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D62898/new/

https://reviews.llvm.org/D62898

Files:
  test/tools/llvm-objcopy/ELF/invalid-p_filesz-p_offset.test
  tools/llvm-objcopy/ELF/Object.cpp


Index: tools/llvm-objcopy/ELF/Object.cpp
===================================================================
--- tools/llvm-objcopy/ELF/Object.cpp
+++ tools/llvm-objcopy/ELF/Object.cpp
@@ -1104,6 +1104,11 @@
 template <class ELFT> void ELFBuilder<ELFT>::readProgramHeaders() {
   uint32_t Index = 0;
   for (const auto &Phdr : unwrapOrError(ElfFile.program_headers())) {
+    if (Phdr.p_offset + Phdr.p_filesz > ElfFile.getBufSize())
+      error("program header with offset 0x" + Twine::utohexstr(Phdr.p_offset) +
+            " and file size 0x" + Twine::utohexstr(Phdr.p_filesz) +
+            " is malformed");
+
     ArrayRef<uint8_t> Data{ElfFile.base() + Phdr.p_offset,
                            (size_t)Phdr.p_filesz};
     Segment &Seg = Obj.addSegment(Data);
Index: test/tools/llvm-objcopy/ELF/invalid-p_filesz-p_offset.test
===================================================================
--- /dev/null
+++ test/tools/llvm-objcopy/ELF/invalid-p_filesz-p_offset.test
@@ -0,0 +1,45 @@
+## In this case, we have a program header with a file size that
+## overflows the binary size. Check llvm-objcopy doesn't crash
+## and report this error properly.
+
+# RUN: yaml2obj --docnum=1 %s -o %t1.o
+# RUN: not llvm-objcopy %t1.o 2>&1 | FileCheck %s --check-prefix=ERR1
+# ERR1: error: program header with offset 0x1b8 and file size 0x100000 is malformed
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_EXEC
+  Machine: EM_X86_64
+Sections:
+  - Name: .foo
+    Type: SHT_PROGBITS
+ProgramHeaders:
+  - Type:        PT_LOAD
+    FileSize:    0x100000
+    Sections:    
+      - Section: .foo
+
+## A similar case, but now p_offset property of program header is too large.
+
+# RUN: yaml2obj --docnum=2 %s -o %t2.o
+# RUN: not llvm-objcopy %t2.o 2>&1 | FileCheck %s --check-prefix=ERR2
+# ERR2: error: program header with offset 0x100000 and file size 0x1 is malformed
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_EXEC
+  Machine: EM_X86_64
+Sections:
+  - Name: .foo
+    Type: SHT_PROGBITS
+    Size: 1
+ProgramHeaders:
+  - Type:        PT_LOAD
+    Offset:      0x100000
+    FileSize:    1
+    Sections:
+      - Section: .foo


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