26d8253ac6
members of the ELF Executable Header inside the library-private
`struct _Elf' descriptor and only update the underlying Elf{32,64}_Ehdr
structure on an elf_update(3) call. These fields of the Ehdr
structure are technically `out of bounds' for an application program
per the ELF(3) API, but we've seen applications that initialize
a new Ehdr structure using memcpy(), messing up the library's
invariants. [1]
Implement elf_getphnum() and handle ELF objects with more than
64K program header table entries.
Reported by: jb [1]
158 lines
4.0 KiB
C
158 lines
4.0 KiB
C
/*-
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* Copyright (c) 2006 Joseph Koshy
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <assert.h>
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#include <gelf.h>
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#include <libelf.h>
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#include <stdlib.h>
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#include "_libelf.h"
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void *
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_libelf_getphdr(Elf *e, int ec)
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{
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size_t phnum, phentsize;
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size_t fsz, msz;
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uint64_t phoff;
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Elf32_Ehdr *eh32;
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Elf64_Ehdr *eh64;
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void *ehdr, *phdr;
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void (*xlator)(char *_d, char *_s, size_t _c, int _swap);
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assert(ec == ELFCLASS32 || ec == ELFCLASS64);
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if (e == NULL) {
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LIBELF_SET_ERROR(ARGUMENT, 0);
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return (NULL);
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}
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if ((phdr = (ec == ELFCLASS32 ?
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(void *) e->e_u.e_elf.e_phdr.e_phdr32 :
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(void *) e->e_u.e_elf.e_phdr.e_phdr64)) != NULL)
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return (phdr);
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/*
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* Check the PHDR related fields in the EHDR for sanity.
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*/
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if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL)
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return (NULL);
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phnum = e->e_u.e_elf.e_nphdr;
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if (ec == ELFCLASS32) {
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eh32 = (Elf32_Ehdr *) ehdr;
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phentsize = eh32->e_phentsize;
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phoff = (uint64_t) eh32->e_phoff;
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} else {
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eh64 = (Elf64_Ehdr *) ehdr;
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phentsize = eh64->e_phentsize;
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phoff = (uint64_t) eh64->e_phoff;
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}
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fsz = gelf_fsize(e, ELF_T_PHDR, phnum, e->e_version);
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assert(fsz > 0);
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if ((uint64_t) e->e_rawsize < (phoff + fsz)) {
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LIBELF_SET_ERROR(HEADER, 0);
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return (NULL);
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}
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msz = _libelf_msize(ELF_T_PHDR, ec, EV_CURRENT);
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assert(msz > 0);
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if ((phdr = calloc(phnum, msz)) == NULL) {
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LIBELF_SET_ERROR(RESOURCE, 0);
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return (NULL);
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}
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if (ec == ELFCLASS32)
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e->e_u.e_elf.e_phdr.e_phdr32 = phdr;
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else
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e->e_u.e_elf.e_phdr.e_phdr64 = phdr;
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xlator = _libelf_get_translator(ELF_T_PHDR, ELF_TOMEMORY, ec);
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(*xlator)(phdr, e->e_rawfile + phoff, phnum,
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e->e_byteorder != LIBELF_PRIVATE(byteorder));
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return (phdr);
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}
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void *
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_libelf_newphdr(Elf *e, int ec, size_t count)
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{
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void *ehdr, *newphdr, *oldphdr;
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size_t msz;
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if (e == NULL) {
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LIBELF_SET_ERROR(ARGUMENT, 0);
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return (NULL);
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}
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if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL) {
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LIBELF_SET_ERROR(SEQUENCE, 0);
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return (NULL);
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}
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assert(e->e_class == ec);
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assert(ec == ELFCLASS32 || ec == ELFCLASS64);
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assert(e->e_version == EV_CURRENT);
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msz = _libelf_msize(ELF_T_PHDR, ec, e->e_version);
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assert(msz > 0);
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newphdr = NULL;
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if (count > 0 && (newphdr = calloc(count, msz)) == NULL) {
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LIBELF_SET_ERROR(RESOURCE, 0);
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return (NULL);
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}
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if (ec == ELFCLASS32) {
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if ((oldphdr = (void *) e->e_u.e_elf.e_phdr.e_phdr32) != NULL)
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free(oldphdr);
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e->e_u.e_elf.e_phdr.e_phdr32 = (Elf32_Phdr *) newphdr;
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} else {
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if ((oldphdr = (void *) e->e_u.e_elf.e_phdr.e_phdr64) != NULL)
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free(oldphdr);
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e->e_u.e_elf.e_phdr.e_phdr64 = (Elf64_Phdr *) newphdr;
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}
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e->e_u.e_elf.e_nphdr = count;
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elf_flagphdr(e, ELF_C_SET, ELF_F_DIRTY);
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return (newphdr);
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}
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