Dear all, Using AFLFast (https://github.com/mboehme/aflfast), a fork of AFL, we found an input causing objdump to crash. Valgrind says that it is an invalid write. The bug was found on Ubuntu 14.04 & binutils was checked out from https://github.com/bminor/binutils-gdb repository. Its commit is 268ebe95201d2ebdcf68cad9dc67ff6d1e25be9e (Fri Nov 18 14:15:12 2016) To reproduce: printf "\x07\x01\x00\x30\x04\x00\x00\x00\x1a\x00\x00\x00\x30\x30\x30\x30\x0d\x00\x00\x00\x30\x30\x30\x30\x04\x00\x00\x00\x40\x00\x00\x00\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x00\x00\x00\x00\x24\x30\x30\x30\x30\x30\x30\x30\x30\x04\x00\x00\x00" > fd objdump -x -l fd ASAN says: ../../bfd/aoutx.h:2832:11: runtime error: store to null pointer of type 'char' Valgrind says: ==52909== Invalid write of size 1 ==52909== at 0x7F8349: aout_32_find_nearest_line (aoutx.h:2832) ==52909== by 0x41C8A9: dump_reloc_set (objdump.c:3162) ==52909== by 0x41E502: dump_relocs_in_section (objdump.c:3328) ==52909== by 0x5FB3AB: bfd_map_over_sections (section.c:1395) ==52909== by 0x422A9E: dump_relocs (objdump.c:3337) ==52909== by 0x422A9E: dump_bfd (objdump.c:3463) ==52909== by 0x4234FF: display_object_bfd (objdump.c:3526) ==52909== by 0x4234FF: display_any_bfd (objdump.c:3615) ==52909== by 0x40CFC9: display_file (objdump.c:3636) ==52909== by 0x40CFC9: main (objdump.c:3919) ==52909== Address 0x0 is not stack'd, malloc'd or (recently) free'd ==52909== ==52909== ==52909== Process terminating with default action of signal 11 (SIGSEGV) ==52909== Access not within mapped region at address 0x0 ==52909== at 0x7F8349: aout_32_find_nearest_line (aoutx.h:2832) ==52909== by 0x41C8A9: dump_reloc_set (objdump.c:3162) ==52909== by 0x41E502: dump_relocs_in_section (objdump.c:3328) ==52909== by 0x5FB3AB: bfd_map_over_sections (section.c:1395) ==52909== by 0x422A9E: dump_relocs (objdump.c:3337) ==52909== by 0x422A9E: dump_bfd (objdump.c:3463) ==52909== by 0x4234FF: display_object_bfd (objdump.c:3526) ==52909== by 0x4234FF: display_any_bfd (objdump.c:3615) ==52909== by 0x40CFC9: display_file (objdump.c:3636) ==52909== by 0x40CFC9: main (objdump.c:3919)
The master branch has been updated by Nick Clifton <nickc@sourceware.org>: https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=e82ab856bb4689330c29fb9f1c57a8555b26380e commit e82ab856bb4689330c29fb9f1c57a8555b26380e Author: Nick Clifton <nickc@redhat.com> Date: Thu Dec 1 10:49:39 2016 +0000 Fix a seg-fault disassembling a corrupt binary. PR binutils/20892 * aoutx.h (find_nearest_line): Handle the case where the function name is empty.
Hi Thuan, Thanks for reporting this bug. I have checked in a small patch that adds a check for a NULL buffer pointer and then repsonds appropriately. Cheers Nick
This is CVE-2017-7224
The master branch has been updated by Stephen Casner <slcasner@sourceware.org>: https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=31af1e68af26f5cae209de3530d0455b8a944b2d commit 31af1e68af26f5cae209de3530d0455b8a944b2d Author: Stephen Casner <casner@acm.org> Date: Wed Jun 3 17:43:45 2020 -0700 Copy several years of fixes from bfd/aoutx.h to bfd/pdp11.c. * pdp11.c (some_aout_object_p): 4c1534c7a2a - Don't set EXEC_P for files with relocs. (aout_get_external_symbols): 6b8f0fd579d - Return if count is zero. 0301ce1486b PR 22306 - Handle stringsize of zero, and error for any other size that doesn't qcover the header word. bf82069dce1 PR 23056 - Allocate an extra byte at the end of the string table, and zero it. (translate_symbol_table): 0d329c0a83a PR 22887 - Print an error message and set bfd_error on finding an invalid name string offset. (add_to_stringtab): INLINE -> inline (pdp11_aout_swap_reloc_in): 116acb2c268 PR 22887 - Correct r_index bound check. (squirt_out_relocs): e2996cc315d PR 20921 - Check for and report any relocs that could not be recognised. 92744f05809 PR 20929 - Check for relocs without an associated symbol. (find_nearest_line): 808346fcfcf PR 23055 - Check that the symbol name exists and is long enough, before attempting to see if it is for a .o file. c3864421222 - Correct case for N_SO being the last symbol. 50455f1ab29 PR 20891 - Handle the case where the main file name and the directory name are both empty. e82ab856bb4 PR 20892 - Handle the case where function name is empty. (aout_link_add_symbols): e517df3dbf7 PR 19629 - Check for out of range string table offsets. 531336e3a0b PR 20909 - Fix off-by-one error in check for an illegal string offset. (aout_link_includes_newfunc): Add comment. (pdp11_aout_link_input_section): ad756e3f9e6 - Return with an error on unexpected relocation type rather than ASSERT.