binutils: Fix CVE-2017-6965 and CVE-2017-6966

binutils: Fix CVE-2017-6965 and CVE-2017-6966

Backport upstream commit to address vulnerabilities:

CVE: CVE-2017-6965
[BZ 21137] -- https://sourceware.org/bugzilla/show_bug.cgi?id=21137

Fix readelf writing to illegal addresses whilst processing corrupt input
files containing symbol-difference relocations.

	PR binutils/21137
	* readelf.c (target_specific_reloc_handling): Add end parameter.
	Check for buffer overflow before writing relocated values.
	(apply_relocations): Pass end to target_specific_reloc_handling.

CVE: CVE-2017-6966
[BZ 21139] -- https://sourceware.org/bugzilla/show_bug.cgi?id=21139

Fix read-after-free error in readelf when processing multiple, relocated
sections in an MSP430 binary.

	PR binutils/21139
	* readelf.c (target_specific_reloc_handling): Add num_syms
	parameter.  Check for symbol table overflow before accessing
	symbol value.  If reloc pointer is NULL, discard all saved state.
	(apply_relocations): Pass num_syms to target_specific_reloc_handling.
	Call target_specific_reloc_handling with a NULL reloc pointer
	after processing all of the relocs.

Signed-off-by: Yuanjie Huang <yuanjie.huang@windriver.com>
Signed-off-by: Armin Kuster <akuster808@gmail.com>