Prevent a null BFD pointer dereference and a resulting segmentation
fault in `mips_elf64_write_rel' or `mips_elf64_write_rela':
Program received signal SIGSEGV, Segmentation fault.
0x0000000000437690 in mips_elf64_write_rela (abfd=0x71e130, sec=0x720700,
rela_hdr=0x721ff8, count=0x7fffffffb82c, data=0x7fffffffb88c)
at .../bfd/elf64-mips.c:4123
4123 if ((*ptr->sym_ptr_ptr)->the_bfd->xvec != abfd->xvec
4124 && ! _bfd_elf_validate_reloc (abfd, ptr))
in the MIPS64 (n64 MIPS) ELF backend whenever the STN_UNDEF symbol index
is retrieved from the `r_sym' field of a relocation seen in input while
running `objcopy' or `strip'. The reason for the null BFD pointer is
that internally in BFD an STN_UNDEF symbol reference resolves to an
absolute zero symbol that does not have a BFD associated. Check the
pointer then before using it, like the generic ELF backend does in
`elf_write_relocs'.
This complements the same change made for generic ELF bundled with:
commit e35765a9a2eaff0df62757f3e6480c8ba5ab8ee8
Author: Ian Lance Taylor <ian@airs.com>
Date: Sun Dec 15 19:59:18 1996 +0000
which (obviously due to a CVS -> GIT repository conversion inaccuracy)
seems to be one corresponding to this ChangeLog entry:
* elfcode.h (write_relocs): Handle absolute symbol.
from:
commit c86158e591edd8450f49f8cd75f82e4313d4b6d8
Author: Ian Lance Taylor <ian@airs.com>
Date: Fri Aug 30 22:09:51 1996 +0000
("Add SH ELF support."), which also updated RELA only and not REL (which
has been since fixed with: commit 947216bf8f34 ("ELF reloc code tidy"),
<https://sourceware.org/ml/binutils/2002-11/msg00727.html>).
bfd/
* elf64-mips.c (mips_elf64_write_rel): Handle a NULL BFD pointer
in the BFD symbol referred by the relocation.
(mips_elf64_write_rela): Likewise.
This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.
BFD is an object file library. It permits applications to use the
same routines to process object files regardless of their format.
BFD is used by the GNU debugger, assembler, linker, and the binary
utilities.
The documentation on using BFD is scanty and may be occasionally
incorrect. Pointers to documentation problems, or an entirely
rewritten manual, would be appreciated.
There is some BFD internals documentation in doc/bfdint.texi which may
help programmers who want to modify BFD.
BFD is normally built as part of another package. See the build
instructions for that package, probably in a README file in the
appropriate directory.
BFD supports the following configure options:
--target=TARGET
The default target for which to build the library. TARGET is
a configuration target triplet, such as sparc-sun-solaris.
--enable-targets=TARGET,TARGET,TARGET...
Additional targets the library should support. To include
support for all known targets, use --enable-targets=all.
--enable-64-bit-bfd
Include support for 64 bit targets. This is automatically
turned on if you explicitly request a 64 bit target, but not
for --enable-targets=all. This requires a compiler with a 64
bit integer type, such as gcc.
--enable-shared
Build BFD as a shared library.
--with-mmap
Use mmap when accessing files. This is faster on some hosts,
but slower on others. It may not work on all hosts.
Report bugs with BFD to bug-binutils@gnu.org.
Patches are encouraged. When sending patches, always send the output
of diff -u or diff -c from the original file to the new file. Do not
send default diff output. Do not make the diff from the new file to
the original file. Remember that any patch must not break other
systems. Remember that BFD must support cross compilation from any
host to any target, so patches which use ``#ifdef HOST'' are not
acceptable. Please also read the ``Reporting Bugs'' section of the
gcc manual.
Bug reports without patches will be remembered, but they may never get
fixed until somebody volunteers to fix them.
Copyright (C) 2012-2018 Free Software Foundation, Inc.
Copying and distribution of this file, with or without modification,
are permitted in any medium without royalty provided the copyright
notice and this notice are preserved.
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