mirror of
https://github.com/openharmony/third_party_elfutils.git
synced 2026-07-01 06:41:51 -04:00
John Ogness
96e140f668
When getting section headers it is assumed that the first section is on the first section list. However, it is possible that the first section list only contains the zeroth section, in which case either illegal memory access occurs or elf_nextscn() erroneously returns NULL. With this patch, checks are added to avoid the illegal memory access and (if available) the second section list is looked at to find the first section. A new test emptyfile is added that tests adding a section to and "empty" ELF file 32/64 class with ELF_C_RDWR[_MMAP]. Signed-off-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: Mark Wielaard <mjw@redhat.com>
84 lines
2.2 KiB
C
84 lines
2.2 KiB
C
/* Get next section.
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Copyright (C) 1998, 1999, 2000, 2001, 2002, 2015 Red Hat, Inc.
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This file is part of elfutils.
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Contributed by Ulrich Drepper <drepper@redhat.com>, 1998.
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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 <libelf.h>
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#include <stddef.h>
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#include "libelfP.h"
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Elf_Scn *
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elf_nextscn (Elf *elf, Elf_Scn *scn)
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{
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Elf_ScnList *list;
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Elf_Scn *result = NULL;
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if (elf == NULL)
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return NULL;
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rwlock_rdlock (elf->lock);
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if (scn == NULL)
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{
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/* If no section handle is given return the first (not 0th) section.
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Set scn to the 0th section and perform nextscn. */
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if (elf->class == ELFCLASS32
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|| (offsetof (Elf, state.elf32.scns)
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== offsetof (Elf, state.elf64.scns)))
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list = &elf->state.elf32.scns;
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else
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list = &elf->state.elf64.scns;
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scn = &list->data[0];
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}
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else
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list = scn->list;
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if (scn + 1 < &list->data[list->cnt])
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result = scn + 1;
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else if (scn + 1 == &list->data[list->max]
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&& (list = list->next) != NULL)
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{
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/* If there is another element in the section list it must
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have at least one entry. */
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assert (list->cnt > 0);
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result = &list->data[0];
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}
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rwlock_unlock (elf->lock);
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return result;
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}
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INTDEF(elf_nextscn)
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