IABSD.fr/src/lib/libelf/libelf_extended.c

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• Author : jsg
  Date : 2019-03-19 02:31:35
  Hash : e219834f
  Message : update libelf from elftoolchain r3669 to r3714 includes changes to address problems sunil@ found with fuzzing original diff from and ok sunil@

• lib/libelf/libelf_extended.c

• /*-
   * Copyright (c) 2006,2008 Joseph Koshy
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   */
  
  #include <assert.h>
  #include <libelf.h>
  
  #include "_libelf.h"
  
  ELFTC_VCSID("$Id: libelf_extended.c,v 1.2 2019/03/19 02:31:35 jsg Exp $");
  
  /*
   * Retrieve section #0, allocating a new section if needed.
   */
  static Elf_Scn *
  _libelf_getscn0(Elf *e)
  {
  	Elf_Scn *s;
  
  	if ((s = STAILQ_FIRST(&e->e_u.e_elf.e_scn)) != NULL)
  		return (s);
  
  	return (_libelf_allocate_scn(e, (size_t) SHN_UNDEF));
  }
  
  int
  _libelf_setshnum(Elf *e, void *eh, int ec, size_t shnum)
  {
  	Elf_Scn *scn;
  
  	if (shnum >= SHN_LORESERVE) {
  		if ((scn = _libelf_getscn0(e)) == NULL)
  			return (0);
  
  		assert(scn->s_ndx == SHN_UNDEF);
  
  		if (ec == ELFCLASS32)
  			scn->s_shdr.s_shdr32.sh_size = (Elf32_Word) shnum;
  		else
  			scn->s_shdr.s_shdr64.sh_size = shnum;
  
  		(void) elf_flagshdr(scn, ELF_C_SET, ELF_F_DIRTY);
  
  		shnum = 0;
  	}
  
  	if (ec == ELFCLASS32)
  		((Elf32_Ehdr *) eh)->e_shnum = shnum & 0xFFFFU;
  	else
  		((Elf64_Ehdr *) eh)->e_shnum = shnum & 0xFFFFU;
  
  
  	return (1);
  }
  
  int
  _libelf_setshstrndx(Elf *e, void *eh, int ec, size_t shstrndx)
  {
  	Elf_Scn *scn;
  
  	if (shstrndx >= SHN_LORESERVE) {
  		if ((scn = _libelf_getscn0(e)) == NULL)
  			return (0);
  
  		assert(scn->s_ndx == SHN_UNDEF);
  
  		if (ec == ELFCLASS32)
  			scn->s_shdr.s_shdr32.sh_link = (Elf32_Word) shstrndx;
  		else
  			scn->s_shdr.s_shdr64.sh_link = (Elf64_Word) shstrndx;
  
  		(void) elf_flagshdr(scn, ELF_C_SET, ELF_F_DIRTY);
  
  		shstrndx = SHN_XINDEX;
  	}
  
  	if (ec == ELFCLASS32)
  		((Elf32_Ehdr *) eh)->e_shstrndx = shstrndx & 0xFFFFU;
  	else
  		((Elf64_Ehdr *) eh)->e_shstrndx = shstrndx & 0xFFFFU;
  
  	return (1);
  }
  
  int
  _libelf_setphnum(Elf *e, void *eh, int ec, size_t phnum)
  {
  	Elf_Scn *scn;
  
  	if (phnum >= PN_XNUM) {
  		if ((scn = _libelf_getscn0(e)) == NULL)
  			return (0);
  
  		assert(scn->s_ndx == SHN_UNDEF);
  
  		if (ec == ELFCLASS32)
  			scn->s_shdr.s_shdr32.sh_info = (Elf32_Word) phnum;
  		else
  			scn->s_shdr.s_shdr64.sh_info = (Elf64_Word) phnum;
  
  		(void) elf_flagshdr(scn, ELF_C_SET, ELF_F_DIRTY);
  
  		phnum = PN_XNUM;
  	}
  
  	if (ec == ELFCLASS32)
  		((Elf32_Ehdr *) eh)->e_phnum = phnum & 0xFFFFU;
  	else
  		((Elf64_Ehdr *) eh)->e_phnum = phnum & 0xFFFFU;
  
  	return (1);
  }