https://sourceware.org/bugzilla/show_bug.cgi?id=34835

            Bug ID: 34835
           Summary: GNU ld PPC64 dereferences a NULL symbol-hash array for
                    an empty symbol table
           Product: binutils
           Version: 2.46
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: ld
          Assignee: unassigned at sourceware dot org
          Reporter: basavesh.shivakumar at wsu dot edu
  Target Milestone: ---

Created attachment 17155
  --> https://sourceware.org/bugzilla/attachment.cgi?id=17155&action=edit
repro

I'm reporting this bug on behalf of my team: Ananta Srikar Puranam, Emily West,
Dr. Swarn Priya, Dr. Peng Gao and Dr. Basavesh Ammanaghatta Shivakumar.

Summary
=======

An ELF64 PPC64 relocation against symbol zero with sh_info zero and a
zero-sized symbol table makes ppc64_elf_check_relocs index a NULL sym_hashes
array at elf64-ppc.c:4819; current ASan/UBSan attributes a zero-page read,
unsanitized current and released GNU ld 2.46 SIGSEGV in final-link modes, a
one-byte populated malformed control is rejected cleanly, and a valid control
links.

Reproduction
============

1. Download and extract
`bfd-ppc64-empty-symtab-null-hash-array-reproducer.tar.gz`.
2. Run the following command with an ld.bfd or all-target `ld-new` binary that
   supports the emulation used by the reproducer:

       BFD=/path/to/ld-new sh repro.sh

The archive contains the fixed input files, independent controls, helper
scripts needed by `repro.sh`, and their checksums. The script uses a temporary
directory and does not modify the source tree.

Observed result
===============

An ELF64 PPC64 relocation against symbol zero with sh_info zero and a
zero-sized symbol table makes ppc64_elf_check_relocs index a NULL sym_hashes
array at elf64-ppc.c:4819; current ASan/UBSan attributes a zero-page read,
unsanitized current and released GNU ld 2.46 SIGSEGV in final-link modes, a
one-byte populated malformed control is rejected cleanly, and a valid control
links.

Expected result
===============

GNU ld should either produce the correct output or reject the input with a
normal diagnostic. It should not crash, hang, execute undefined behavior, read
outside an input-derived allocation, or produce the described malformed
output.

-- 
You are receiving this mail because:
You are on the CC list for the bug.

Reply via email to