[PATCH] [Request, 3 lines] D25091: [Object/ELF] - Do not crash if string table sh_size is equal to zero.

[George Rimar via llvm-commits]

grimar created this revision.
grimar added reviewers: rafael, davide.
grimar added subscribers: llvm-commits, grimar, evgeny777.

Revealed using "id_000038,sig_11,src_000015,op_havoc,rep_16" from PR30540,
when sh_size was 0, crash happened.


https://reviews.llvm.org/D25091

Files:
  include/llvm/Object/ELF.h
  test/Object/Inputs/invalid-strtab-zero-size.elf
  test/Object/invalid.test


Index: test/Object/invalid.test
===================================================================
--- test/Object/invalid.test
+++ test/Object/invalid.test
@@ -1,6 +1,7 @@
 RUN: not llvm-dwarfdump %p/Inputs/invalid-bad-rel-type.elf 2>&1 | FileCheck %s
 RUN: not llvm-objdump -s %p/Inputs/invalid-strtab-type.elf 2>&1 | FileCheck %s
 RUN: not llvm-objdump -s %p/Inputs/invalid-strtab-size.elf 2>&1 | FileCheck %s
+RUN: not llvm-objdump -s %p/Inputs/invalid-strtab-zero-size.elf 2>&1 | FileCheck %s
 CHECK: Invalid data was encountered while parsing the file
 
 RUN: not llvm-objdump -s %p/Inputs/invalid-strtab-non-null.elf 2>&1 | FileCheck --check-prefix=NON-NULL %s
Index: include/llvm/Object/ELF.h
===================================================================
--- include/llvm/Object/ELF.h
+++ include/llvm/Object/ELF.h
@@ -437,7 +437,7 @@
     return object_error::parse_failed;
   uint64_t Offset = Section->sh_offset;
   uint64_t Size = Section->sh_size;
-  if (Offset + Size > Buf.size())
+  if (!Size || Offset + Size > Buf.size())
     return object_error::parse_failed;
   StringRef Data((const char *)base() + Section->sh_offset, Size);
   if (Data[Size - 1] != '\0')


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