mirror of
https://github.com/openharmony/third_party_elfutils.git
synced 2026-07-18 17:24:31 -04:00
Mark Wielaard
8b5f017ddf
elf[32|64]_updatenull would sanity check the e_type before allowing to update the phdrs. This prevents creating an ET_REL file with phdrs. It also prevents creating any vendor specific ELF file having phdrs. We only check this when updating/writing out the file. But we would just read such files. Don't prevent people from creating unexpected ELF files. elflint will warn for such files. While writing a new testcase for this another bug was found that prevented updating a just created phdr because elf_getphdrnum would sanity check the phdr offset in the file (which doesn't exist yet). Fix that by only doing such a sanity check if the phdrs haven't been read in or created yet. This second bug should have been found by the existing elfshphehdr test, but that test contained a typo checking elf_getphdrnum. It tested that the called failed when there were no phdrs, but then elf_getphdrnum should simply succeed and return zero. https://bugzilla.redhat.com/show_bug.cgi?id=1352232 Signed-off-by: Mark Wielaard <mjw@redhat.com>
143 lines
3.6 KiB
C
143 lines
3.6 KiB
C
/* Return number of program headers in the ELF file.
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Copyright (C) 2010, 2014, 2015, 2016 Red Hat, Inc.
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This file is part of elfutils.
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This file is free software; you can redistribute it and/or modify
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it under the terms of either
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* the GNU Lesser General Public License as published by the Free
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Software Foundation; either version 3 of the License, or (at
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your option) any later version
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or
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* the GNU General Public License as published by the Free
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Software Foundation; either version 2 of the License, or (at
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your option) any later version
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or both in parallel, as here.
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elfutils is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received copies of the GNU General Public License and
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the GNU Lesser General Public License along with this program. If
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not, see <http://www.gnu.org/licenses/>. */
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#ifdef HAVE_CONFIG_H
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# include <config.h>
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#endif
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#include <assert.h>
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#include <gelf.h>
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#include <stddef.h>
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#include "libelfP.h"
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int
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internal_function
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__elf_getphdrnum_rdlock (Elf *elf, size_t *dst)
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{
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if (unlikely (elf->state.elf64.ehdr == NULL))
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{
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/* Maybe no ELF header was created yet. */
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__libelf_seterrno (ELF_E_WRONG_ORDER_EHDR);
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return -1;
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}
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*dst = (elf->class == ELFCLASS32
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? elf->state.elf32.ehdr->e_phnum
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: elf->state.elf64.ehdr->e_phnum);
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if (*dst == PN_XNUM)
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{
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const Elf_ScnList *const scns = (elf->class == ELFCLASS32
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? &elf->state.elf32.scns
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: &elf->state.elf64.scns);
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/* If there are no section headers, perhaps this is really just 65536
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written without PN_XNUM support. Either that or it's bad data. */
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if (elf->class == ELFCLASS32)
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{
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if (likely (scns->cnt > 0
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&& elf->state.elf32.scns.data[0].shdr.e32 != NULL))
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*dst = scns->data[0].shdr.e32->sh_info;
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}
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else
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{
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if (likely (scns->cnt > 0
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&& elf->state.elf64.scns.data[0].shdr.e64 != NULL))
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*dst = scns->data[0].shdr.e64->sh_info;
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}
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}
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return 0;
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}
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int
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internal_function
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__elf_getphdrnum_chk_rdlock (Elf *elf, size_t *dst)
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{
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int result = __elf_getphdrnum_rdlock (elf, dst);
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/* If the phdrs haven't been created or read in yet then do some
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sanity checking to make sure phnum and phoff are consistent. */
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if (elf->state.elf.phdr == NULL)
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{
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Elf64_Off off = (elf->class == ELFCLASS32
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? elf->state.elf32.ehdr->e_phoff
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: elf->state.elf64.ehdr->e_phoff);
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if (unlikely (off == 0))
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{
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*dst = 0;
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return result;
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}
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if (unlikely (off >= elf->maximum_size))
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{
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__libelf_seterrno (ELF_E_INVALID_DATA);
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return -1;
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}
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/* Check for too many sections. */
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size_t phdr_size = (elf->class == ELFCLASS32
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? sizeof (Elf32_Phdr) : sizeof (Elf64_Phdr));
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if (unlikely (*dst > SIZE_MAX / phdr_size))
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{
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__libelf_seterrno (ELF_E_INVALID_DATA);
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return -1;
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}
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/* Truncated file? Don't return more than can be indexed. */
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if (unlikely (elf->maximum_size - off < *dst * phdr_size))
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*dst = (elf->maximum_size - off) / phdr_size;
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}
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return result;
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}
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int
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elf_getphdrnum (Elf *elf, size_t *dst)
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{
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int result;
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if (elf == NULL)
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return -1;
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if (unlikely (elf->kind != ELF_K_ELF))
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{
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__libelf_seterrno (ELF_E_INVALID_HANDLE);
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return -1;
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}
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rwlock_rdlock (elf->lock);
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result = __elf_getphdrnum_chk_rdlock (elf, dst);
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rwlock_unlock (elf->lock);
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return result;
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}
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