When I test latest objcopy with elf file, there is null pointer dereference problem. Here is part of output. ==23042==ERROR: AddressSanitizer: SEGV on unknown address 0x00000038 (pc 0x082cd8d8 bp 0x1ea219a1 sp 0xffa84c10 T0) #0 0x82cd8d7 in assign_file_positions_for_non_load_sections /work/binutils-gdb/bfd/elf.c:5908 #1 0x82cd8d7 in assign_file_positions_except_relocs /work/binutils-gdb/bfd/elf.c:6093 #2 0x82cd8d7 in _bfd_elf_compute_section_file_positions /work/binutils-gdb/bfd/elf.c:4260 #3 0x82ffe3a in _bfd_elf_set_section_contents /work/binutils-gdb/bfd/elf.c:8839 #4 0x81ba6ee in bfd_set_section_contents /work/binutils-gdb/bfd/section.c:1532 #5 0x806a3be in copy_section /work/binutils-gdb/binutils/objcopy.c:4099 #6 0x81b9f44 in bfd_map_over_sections /work/binutils-gdb/bfd/section.c:1394 #7 0x80743ac in copy_object /work/binutils-gdb/binutils/objcopy.c:3048 #8 0x808087b in copy_object /work/binutils-gdb/binutils/objcopy.c:2432 #9 0x808087b in copy_file /work/binutils-gdb/binutils/objcopy.c:3523 #10 0x805596c in copy_main /work/binutils-gdb/binutils/objcopy.c:5478 #11 0x805596c in main /work/binutils-gdb/binutils/objcopy.c:5582 #12 0xf70af636 in __libc_start_main (/lib/i386-linux-gnu/libc.so.6+0x18636) #13 0x8060dc5 (/work/build/binutils/objcopy+0x8060dc5) The snippt of function assign_file_positions_for_non_load_sections. (gdb) list 5903 break; 5904 } 5905 BFD_ASSERT (lm != NULL); 5906 5907 /* Find the section starting the RELRO segment. */ 5908 for (i = 0; i < lm->count; i++) 5909 { 5910 asection *s = lm->sections[i]; 5911 if (s->vma >= start 5912 && s->vma < end It seems that BFD_ASSERT(lm != NULL) doesn't end the execution which leads to null pointer dereference. The test command is `objcopy test.elf` and the test elf file is https://github.com/skysider/FuzzVuln/blob/master/binutils_objcopy_null_pointer_dereference_assign_file_positions_for_non_load_sections.elf
The master branch has been updated by Alan Modra <amodra@sourceware.org>: https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=01f7e10cf2dcf403462b2feed06c43135651556d commit 01f7e10cf2dcf403462b2feed06c43135651556d Author: Alan Modra <amodra@gmail.com> Date: Fri Feb 23 21:22:43 2018 +1030 PR22881, null pointer dereference in assign_file_positions_for_non_load_sections PR 22881 * elf.c (assign_file_positions_for_non_load_sections): Remove RELRO segment if no matching LOAD segment.
fixed