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View File elfutils-robustify.patch of Package elfutils (Project Ports:ARM:Base:build:cross)

From: unknown
Subject: elfutils robustness
Upstream: no
References: https://fedorahosted.org/releases/e/l/elfutils/0.158/elfutils-robustify.patch
Signed-off-by: Tony Jones <tonyj@suse.de>

Various robustness fixes not deemed acceptable for inclusion into git repo.

---
 libdwfl/ChangeLog             |    5 +
 libdwfl/relocate.c            |    9 ++-
 libelf/ChangeLog              |   43 +++++++++++++++
 libelf/elf32_getphdr.c        |   10 +++
 libelf/elf32_getshdr.c        |   13 ++++
 libelf/elf32_newphdr.c        |    6 ++
 libelf/elf32_updatefile.c     |    7 ++
 libelf/elf_begin.c            |   30 ++++++++++
 libelf/elf_getarsym.c         |    3 +
 libelf/elf_getshdrstrndx.c    |   42 ++++++++++++---
 libelf/elf_newscn.c           |   10 +++
 libelf/gelf_getdyn.c          |    6 +-
 libelf/gelf_getlib.c          |    4 -
 libelf/gelf_getmove.c         |    4 -
 libelf/gelf_getrel.c          |   12 +---
 libelf/gelf_getrela.c         |   12 +---
 libelf/gelf_getsym.c          |    6 +-
 libelf/gelf_getsyminfo.c      |    4 -
 libelf/gelf_getsymshndx.c     |    8 +-
 libelf/gelf_getversym.c       |    4 -
 libelf/gelf_update_dyn.c      |   12 +---
 libelf/gelf_update_lib.c      |   10 ---
 libelf/gelf_update_move.c     |    5 -
 libelf/gelf_update_rel.c      |   12 +---
 libelf/gelf_update_rela.c     |   12 +---
 libelf/gelf_update_sym.c      |   12 +---
 libelf/gelf_update_syminfo.c  |   10 ---
 libelf/gelf_update_symshndx.c |   12 +---
 libelf/gelf_update_versym.c   |    5 -
 libelf/libelfP.h              |    4 +
 src/ChangeLog                 |   29 ++++++++++
 src/elflint.c                 |  103 +++++++++++++++++++++++++++---------
 src/readelf.c                 |  117 +++++++++++++++++++++++++++++-------------
 src/strip.c                   |   80 +++++++++++++++++++---------
 34 files changed, 456 insertions(+), 205 deletions(-)

--- a/libdwfl/ChangeLog
+++ b/libdwfl/ChangeLog
@@ -695,6 +695,11 @@
 	* dwfl_module_getdwarf.c (open_elf): Clear errno before CBFAIL.
 	Reported by Kurt Roeckx <kurt@roeckx.be>.
 
+2011-03-23  Petr Machata  <pmachata@redhat.com>
+
+	* relocate.c (relocate_section): Use gelf_fsize instead of relying
+	on shdr->sh_entsize.
+
 2011-02-11  Roland McGrath  <roland@redhat.com>
 
 	* linux-kernel-modules.c (try_kernel_name): Try .gz, .bz2, .xz
--- a/libdwfl/relocate.c
+++ b/libdwfl/relocate.c
@@ -1,5 +1,5 @@
 /* Relocate debug information.
-   Copyright (C) 2005-2010 Red Hat, Inc.
+   Copyright (C) 2005-2011 Red Hat, Inc.
    This file is part of elfutils.
 
    This file is free software; you can redistribute it and/or modify
@@ -456,7 +456,10 @@ relocate_section (Dwfl_Module *mod, Elf
       }
   }
 
-  size_t nrels = shdr->sh_size / shdr->sh_entsize;
+  size_t sh_entsize
+    = gelf_fsize (relocated, shdr->sh_type == SHT_REL ? ELF_T_REL : ELF_T_RELA,
+		  1, EV_CURRENT);
+  size_t nrels = shdr->sh_size / sh_entsize;
   size_t complete = 0;
   if (shdr->sh_type == SHT_REL)
     for (size_t relidx = 0; !result && relidx < nrels; ++relidx)
@@ -558,7 +561,7 @@ relocate_section (Dwfl_Module *mod, Elf
 	  nrels = next;
 	}
 
-      shdr->sh_size = reldata->d_size = nrels * shdr->sh_entsize;
+      shdr->sh_size = reldata->d_size = nrels * sh_entsize;
       gelf_update_shdr (scn, shdr);
     }
 
--- a/libelf/ChangeLog
+++ b/libelf/ChangeLog
@@ -759,10 +759,53 @@
 	If section content hasn't been read yet, do it before looking for the
 	block size.  If no section data present, infer size of section header.
 
+2005-05-14  Jakub Jelinek  <jakub@redhat.com>
+
+	* libelfP.h (INVALID_NDX): Define.
+	* gelf_getdyn.c (gelf_getdyn): Use it.  Remove ndx < 0 test if any.
+	* gelf_getlib.c (gelf_getlib): Likewise.
+	* gelf_getmove.c (gelf_getmove): Likewise.
+	* gelf_getrel.c (gelf_getrel): Likewise.
+	* gelf_getrela.c (gelf_getrela): Likewise.
+	* gelf_getsym.c (gelf_getsym): Likewise.
+	* gelf_getsyminfo.c (gelf_getsyminfo): Likewise.
+	* gelf_getsymshndx.c (gelf_getsymshndx): Likewise.
+	* gelf_getversym.c (gelf_getversym): Likewise.
+	* gelf_update_dyn.c (gelf_update_dyn): Likewise.
+	* gelf_update_lib.c (gelf_update_lib): Likewise.
+	* gelf_update_move.c (gelf_update_move): Likewise.
+	* gelf_update_rel.c (gelf_update_rel): Likewise.
+	* gelf_update_rela.c (gelf_update_rela): Likewise.
+	* gelf_update_sym.c (gelf_update_sym): Likewise.
+	* gelf_update_syminfo.c (gelf_update_syminfo): Likewise.
+	* gelf_update_symshndx.c (gelf_update_symshndx): Likewise.
+	* gelf_update_versym.c (gelf_update_versym): Likewise.
+	* elf_newscn.c (elf_newscn): Check for overflow.
+	* elf32_updatefile.c (__elfw2(LIBELFBITS,updatemmap)): Likewise.
+	(__elfw2(LIBELFBITS,updatefile)): Likewise.
+	* elf_begin.c (file_read_elf): Likewise.
+	* elf32_newphdr.c (elfw2(LIBELFBITS,newphdr)): Likewise.
+	* elf_getarsym.c (elf_getarsym): Likewise.
+	* elf32_getshdr.c (elfw2(LIBELFBITS,getshdr)): Likewise.
 2005-05-11  Ulrich Drepper  <drepper@redhat.com>
 
 	* elf.h: Update again.
 
+2005-05-17  Jakub Jelinek  <jakub@redhat.com>
+
+	* elf32_getphdr.c (elfw2(LIBELFBITS,getphdr)): Check if program header
+	table fits into object's bounds.
+	* elf_getshstrndx.c (elf_getshstrndx): Add elf->start_offset to
+	elf->map_address.  Check if first section header fits into object's
+	bounds.
+	* elf32_getshdr.c (elfw2(LIBELFBITS,getshdr)):
+	Check if section header table fits into object's bounds.
+	* elf_begin.c (get_shnum): Ensure section headers fits into
+	object's bounds.
+	(file_read_elf): Make sure scncnt is small enough to allocate both
+	ElfXX_Shdr and Elf_Scn array.  Make sure section and program header
+	tables fit into object's bounds.  Avoid memory leak on failure.
+
 2005-05-09  Ulrich Drepper  <drepper@redhat.com>
 
 	* elf.h: Update from glibc.
--- a/libelf/elf32_getphdr.c
+++ b/libelf/elf32_getphdr.c
@@ -93,6 +93,16 @@ __elfw2(LIBELFBITS,getphdr_wrlock) (elf)
 
       if (elf->map_address != NULL)
 	{
+	  /* First see whether the information in the ELF header is
+	     valid and it does not ask for too much.  */
+	  if (unlikely (ehdr->e_phoff >= elf->maximum_size)
+	      || unlikely (elf->maximum_size - ehdr->e_phoff < size))
+	    {
+	      /* Something is wrong.  */
+	      __libelf_seterrno (ELF_E_INVALID_PHDR);
+	      goto out;
+	    }
+
 	  /* All the data is already mapped.  Use it.  */
 	  void *file_phdr = ((char *) elf->map_address
 			     + elf->start_offset + ehdr->e_phoff);
--- a/libelf/elf32_getshdr.c
+++ b/libelf/elf32_getshdr.c
@@ -60,7 +60,8 @@ load_shdr_wrlock (Elf_Scn *scn)
     goto out;
 
   size_t shnum;
-  if (__elf_getshdrnum_rdlock (elf, &shnum) != 0)
+  if (__elf_getshdrnum_rdlock (elf, &shnum) != 0
+      || shnum > SIZE_MAX / sizeof (ElfW2(LIBELFBITS,Shdr)))
     goto out;
   size_t size = shnum * sizeof (ElfW2(LIBELFBITS,Shdr));
 
@@ -77,6 +78,16 @@ load_shdr_wrlock (Elf_Scn *scn)
 
   if (elf->map_address != NULL)
     {
+      /* First see whether the information in the ELF header is
+	 valid and it does not ask for too much.  */
+      if (unlikely (ehdr->e_shoff >= elf->maximum_size)
+	  || unlikely (elf->maximum_size - ehdr->e_shoff < size))
+	{
+	  /* Something is wrong.  */
+	  __libelf_seterrno (ELF_E_INVALID_SECTION_HEADER);
+	  goto free_and_out;
+	}
+
       ElfW2(LIBELFBITS,Shdr) *notcvt;
 
       /* All the data is already mapped.  If we could use it
--- a/libelf/elf32_newphdr.c
+++ b/libelf/elf32_newphdr.c
@@ -114,6 +114,12 @@ elfw2(LIBELFBITS,newphdr) (elf, count)
 	   || count == PN_XNUM
 	   || elf->state.ELFW(elf,LIBELFBITS).phdr == NULL)
     {
+      if (unlikely (count > SIZE_MAX / sizeof (ElfW2(LIBELFBITS,Phdr))))
+	{
+	  result = NULL;
+	  goto out;
+	}
+
       /* Allocate a new program header with the appropriate number of
 	 elements.  */
       result = (ElfW2(LIBELFBITS,Phdr) *)
--- a/libelf/elf32_updatefile.c
+++ b/libelf/elf32_updatefile.c
@@ -202,6 +202,9 @@ __elfw2(LIBELFBITS,updatemmap) (Elf *elf
   /* Write all the sections.  Well, only those which are modified.  */
   if (shnum > 0)
     {
+      if (unlikely (shnum > SIZE_MAX / sizeof (Elf_Scn *)))
+ 	return 1;
+
       Elf_ScnList *list = &elf->state.ELFW(elf,LIBELFBITS).scns;
       Elf_Scn **scns = (Elf_Scn **) alloca (shnum * sizeof (Elf_Scn *));
       char *const shdr_start = ((char *) elf->map_address + elf->start_offset
@@ -624,6 +627,10 @@ __elfw2(LIBELFBITS,updatefile) (Elf *elf
   /* Write all the sections.  Well, only those which are modified.  */
   if (shnum > 0)
     {
+      if (unlikely (shnum > SIZE_MAX / (sizeof (Elf_Scn *)
+					+ sizeof (ElfW2(LIBELFBITS,Shdr)))))
+	return 1;
+
       off_t shdr_offset = elf->start_offset + ehdr->e_shoff;
 #if EV_NUM != 2
       xfct_t shdr_fctp = __elf_xfctstom[__libelf_version - 1][EV_CURRENT - 1][ELFW(ELFCLASS, LIBELFBITS) - 1][ELF_T_SHDR];
--- a/libelf/elf_begin.c
+++ b/libelf/elf_begin.c
@@ -144,7 +144,8 @@ get_shnum (void *map_address, unsigned c
 
       if (unlikely (result == 0) && ehdr.e32->e_shoff != 0)
 	{
-	  if (ehdr.e32->e_shoff + sizeof (Elf32_Shdr) > maxsize)
+	  if (unlikely (ehdr.e32->e_shoff >= maxsize)
+	      || unlikely (maxsize - ehdr.e32->e_shoff < sizeof (Elf32_Shdr)))
 	    /* Cannot read the first section header.  */
 	    return 0;
 
@@ -192,7 +193,8 @@ get_shnum (void *map_address, unsigned c
 
       if (unlikely (result == 0) && ehdr.e64->e_shoff != 0)
 	{
-	  if (ehdr.e64->e_shoff + sizeof (Elf64_Shdr) > maxsize)
+	  if (unlikely (ehdr.e64->e_shoff >= maxsize)
+	      || unlikely (ehdr.e64->e_shoff + sizeof (Elf64_Shdr) > maxsize))
 	    /* Cannot read the first section header.  */
 	    return 0;
 
@@ -264,6 +266,15 @@ file_read_elf (int fildes, void *map_add
     /* Could not determine the number of sections.  */
     return NULL;
 
+  /* Check for too many sections.  */
+  if (e_ident[EI_CLASS] == ELFCLASS32)
+    {
+      if (scncnt > SIZE_MAX / (sizeof (Elf_Scn) + sizeof (Elf32_Shdr)))
+	return NULL;
+    }
+  else if (scncnt > SIZE_MAX / (sizeof (Elf_Scn) + sizeof (Elf64_Shdr)))
+    return NULL;
+
   /* We can now allocate the memory.  Even if there are no section headers,
      we allocate space for a zeroth section in case we need it later.  */
   const size_t scnmax = (scncnt ?: (cmd == ELF_C_RDWR || cmd == ELF_C_RDWR_MMAP)
@@ -303,6 +314,16 @@ file_read_elf (int fildes, void *map_add
 	{
 	  /* We can use the mmapped memory.  */
 	  elf->state.elf32.ehdr = ehdr;
+
+	  if (unlikely (ehdr->e_shoff >= maxsize)
+	      || unlikely (maxsize - ehdr->e_shoff
+			   < scncnt * sizeof (Elf32_Shdr)))
+	    {
+	    free_and_out:
+	      free (elf);
+	      __libelf_seterrno (ELF_E_INVALID_FILE);
+	      return NULL;
+	    }
 	  elf->state.elf32.shdr
 	    = (Elf32_Shdr *) ((char *) ehdr + ehdr->e_shoff);
 
@@ -389,6 +410,11 @@ file_read_elf (int fildes, void *map_add
 	{
 	  /* We can use the mmapped memory.  */
 	  elf->state.elf64.ehdr = ehdr;
+
+	  if (unlikely (ehdr->e_shoff >= maxsize)
+	      || unlikely (ehdr->e_shoff
+			   + scncnt * sizeof (Elf32_Shdr) > maxsize))
+	    goto free_and_out;
 	  elf->state.elf64.shdr
 	    = (Elf64_Shdr *) ((char *) ehdr + ehdr->e_shoff);
 
--- a/libelf/elf_getarsym.c
+++ b/libelf/elf_getarsym.c
@@ -183,6 +183,9 @@ elf_getarsym (elf, ptr)
       size_t index_size = atol (tmpbuf);
 
       if (SARMAG + sizeof (struct ar_hdr) + index_size > elf->maximum_size
+#if SIZE_MAX <= 4294967295U
+	  || n >= SIZE_MAX / sizeof (Elf_Arsym)
+#endif
 	  || n * w > index_size)
 	{
 	  /* This index table cannot be right since it does not fit into
--- a/libelf/elf_getshdrstrndx.c
+++ b/libelf/elf_getshdrstrndx.c
@@ -104,10 +104,25 @@ elf_getshdrstrndx (elf, dst)
 	      if (elf->map_address != NULL
 		  && elf->state.elf32.ehdr->e_ident[EI_DATA] == MY_ELFDATA
 		  && (ALLOW_UNALIGNED
-		      || (((size_t) ((char *) elf->map_address + offset))
+		      || (((size_t) ((char *) elf->map_address
+			   + elf->start_offset + offset))
 			  & (__alignof__ (Elf32_Shdr) - 1)) == 0))
-		/* We can directly access the memory.  */
-		num = ((Elf32_Shdr *) (elf->map_address + offset))->sh_link;
+		{
+		  /* First see whether the information in the ELF header is
+		     valid and it does not ask for too much.  */
+		  if (unlikely (elf->maximum_size - offset
+				< sizeof (Elf32_Shdr)))
+		    {
+		      /* Something is wrong.  */
+		      __libelf_seterrno (ELF_E_INVALID_SECTION_HEADER);
+		      result = -1;
+		      goto out;
+		    }
+
+		  /* We can directly access the memory.  */
+		  num = ((Elf32_Shdr *) (elf->map_address + elf->start_offset
+					 + offset))->sh_link;
+		}
 	      else
 		{
 		  /* We avoid reading in all the section headers.  Just read
@@ -142,10 +157,25 @@ elf_getshdrstrndx (elf, dst)
 	      if (elf->map_address != NULL
 		  && elf->state.elf64.ehdr->e_ident[EI_DATA] == MY_ELFDATA
 		  && (ALLOW_UNALIGNED
-		      || (((size_t) ((char *) elf->map_address + offset))
+		      || (((size_t) ((char *) elf->map_address
+			   + elf->start_offset + offset))
 			  & (__alignof__ (Elf64_Shdr) - 1)) == 0))
-		/* We can directly access the memory.  */
-		num = ((Elf64_Shdr *) (elf->map_address + offset))->sh_link;
+		{
+		  /* First see whether the information in the ELF header is
+		     valid and it does not ask for too much.  */
+		  if (unlikely (elf->maximum_size - offset
+				< sizeof (Elf64_Shdr)))
+		    {
+		      /* Something is wrong.  */
+		      __libelf_seterrno (ELF_E_INVALID_SECTION_HEADER);
+		      result = -1;
+		      goto out;
+		    }
+
+		  /* We can directly access the memory.  */
+		  num = ((Elf64_Shdr *) (elf->map_address + elf->start_offset
+					 + offset))->sh_link;
+		}
 	      else
 		{
 		  /* We avoid reading in all the section headers.  Just read
--- a/libelf/elf_newscn.c
+++ b/libelf/elf_newscn.c
@@ -83,10 +83,18 @@ elf_newscn (elf)
   else
     {
       /* We must allocate a new element.  */
-      Elf_ScnList *newp;
+      Elf_ScnList *newp = NULL;
 
       assert (elf->state.elf.scnincr > 0);
 
+      if (
+#if SIZE_MAX <= 4294967295U
+	  likely (elf->state.elf.scnincr
+		  < SIZE_MAX / 2 / sizeof (Elf_Scn) - sizeof (Elf_ScnList))
+#else
+	  1
+#endif
+	  )
       newp = (Elf_ScnList *) calloc (sizeof (Elf_ScnList)
 				     + ((elf->state.elf.scnincr *= 2)
 					* sizeof (Elf_Scn)), 1);
--- a/libelf/gelf_getdyn.c
+++ b/libelf/gelf_getdyn.c
@@ -1,5 +1,5 @@
 /* Get information from dynamic table at the given index.
-   Copyright (C) 2000, 2001, 2002 Red Hat, Inc.
+   Copyright (C) 2000-2009 Red Hat, Inc.
    This file is part of elfutils.
    Written by Ulrich Drepper <drepper@redhat.com>, 2000.
 
@@ -72,7 +72,7 @@ gelf_getdyn (data, ndx, dst)
 	 table entries has to be adopted.  The user better has provided
 	 a buffer where we can store the information.  While copying the
 	 data we are converting the format.  */
-      if (unlikely ((ndx + 1) * sizeof (Elf32_Dyn) > data_scn->d.d_size))
+      if (INVALID_NDX (ndx, Elf32_Dyn, &data_scn->d))
 	{
 	  __libelf_seterrno (ELF_E_INVALID_INDEX);
 	  goto out;
@@ -93,7 +93,7 @@ gelf_getdyn (data, ndx, dst)
 
       /* The data is already in the correct form.  Just make sure the
 	 index is OK.  */
-      if (unlikely ((ndx + 1) * sizeof (GElf_Dyn) > data_scn->d.d_size))
+      if (INVALID_NDX (ndx, GElf_Dyn, &data_scn->d))
 	{
 	  __libelf_seterrno (ELF_E_INVALID_INDEX);
 	  goto out;
--- a/libelf/gelf_getlib.c
+++ b/libelf/gelf_getlib.c
@@ -1,5 +1,5 @@
 /* Get library from table at the given index.
-   Copyright (C) 2004 Red Hat, Inc.
+   Copyright (C) 2004-2009 Red Hat, Inc.
    This file is part of elfutils.
    Written by Ulrich Drepper <drepper@redhat.com>, 2004.
 
@@ -65,7 +65,7 @@ gelf_getlib (data, ndx, dst)
   /* The data is already in the correct form.  Just make sure the
      index is OK.  */
   GElf_Lib *result = NULL;
-  if (unlikely ((ndx + 1) * sizeof (GElf_Lib) > data->d_size))
+  if (INVALID_NDX (ndx, GElf_Lib, data))
     __libelf_seterrno (ELF_E_INVALID_INDEX);
   else
     {
--- a/libelf/gelf_getmove.c
+++ b/libelf/gelf_getmove.c
@@ -1,5 +1,5 @@
 /* Get move structure at the given index.
-   Copyright (C) 2000, 2001, 2002 Red Hat, Inc.
+   Copyright (C) 2000-2009 Red Hat, Inc.
    This file is part of elfutils.
    Written by Ulrich Drepper <drepper@redhat.com>, 2000.
 
@@ -62,7 +62,7 @@ gelf_getmove (data, ndx, dst)
 
   /* The data is already in the correct form.  Just make sure the
      index is OK.  */
-  if (unlikely ((ndx + 1) * sizeof (GElf_Move) > data->d_size))
+  if (INVALID_NDX (ndx, GElf_Move, data))
     {
       __libelf_seterrno (ELF_E_INVALID_INDEX);
       goto out;
--- a/libelf/gelf_getrela.c
+++ b/libelf/gelf_getrela.c
@@ -1,5 +1,5 @@
 /* Get RELA relocation information at given index.
-   Copyright (C) 2000, 2001, 2002 Red Hat, Inc.
+   Copyright (C) 2000-2009 Red Hat, Inc.
    This file is part of elfutils.
    Written by Ulrich Drepper <drepper@redhat.com>, 2000.
 
@@ -50,12 +50,6 @@ gelf_getrela (data, ndx, dst)
   if (data_scn == NULL)
     return NULL;
 
-  if (unlikely (ndx < 0))
-    {
-      __libelf_seterrno (ELF_E_INVALID_INDEX);
-      return NULL;
-    }
-
   if (unlikely (data_scn->d.d_type != ELF_T_RELA))
     {
       __libelf_seterrno (ELF_E_INVALID_HANDLE);
@@ -72,7 +66,7 @@ gelf_getrela (data, ndx, dst)
   if (scn->elf->class == ELFCLASS32)
     {
       /* We have to convert the data.  */
-      if (unlikely ((ndx + 1) * sizeof (Elf32_Rela) > data_scn->d.d_size))
+      if (INVALID_NDX (ndx, Elf32_Rela, &data_scn->d))
 	{
 	  __libelf_seterrno (ELF_E_INVALID_INDEX);
 	  result = NULL;
@@ -93,7 +87,7 @@ gelf_getrela (data, ndx, dst)
     {
       /* Simply copy the data after we made sure we are actually getting
 	 correct data.  */
-      if (unlikely ((ndx + 1) * sizeof (Elf64_Rela) > data_scn->d.d_size))
+      if (INVALID_NDX (ndx, Elf64_Rela, &data_scn->d))
 	{
 	  __libelf_seterrno (ELF_E_INVALID_INDEX);
 	  result = NULL;
--- a/libelf/gelf_getrel.c
+++ b/libelf/gelf_getrel.c
@@ -1,5 +1,5 @@
 /* Get REL relocation information at given index.
-   Copyright (C) 2000, 2001, 2002 Red Hat, Inc.
+   Copyright (C) 2000-2009 Red Hat, Inc.
    This file is part of elfutils.
    Written by Ulrich Drepper <drepper@redhat.com>, 2000.
 
@@ -50,12 +50,6 @@ gelf_getrel (data, ndx, dst)
   if (data_scn == NULL)
     return NULL;
 
-  if (unlikely (ndx < 0))
-    {
-      __libelf_seterrno (ELF_E_INVALID_INDEX);
-      return NULL;
-    }
-
   if (unlikely (data_scn->d.d_type != ELF_T_REL))
     {
       __libelf_seterrno (ELF_E_INVALID_HANDLE);
@@ -72,7 +66,7 @@ gelf_getrel (data, ndx, dst)
   if (scn->elf->class == ELFCLASS32)
     {
       /* We have to convert the data.  */
-      if (unlikely ((ndx + 1) * sizeof (Elf32_Rel) > data_scn->d.d_size))
+      if (INVALID_NDX (ndx, Elf32_Rel, &data_scn->d))
 	{
 	  __libelf_seterrno (ELF_E_INVALID_INDEX);
 	  result = NULL;
@@ -92,7 +86,7 @@ gelf_getrel (data, ndx, dst)
     {
       /* Simply copy the data after we made sure we are actually getting
 	 correct data.  */
-      if (unlikely ((ndx + 1) * sizeof (Elf64_Rel) > data_scn->d.d_size))
+      if (INVALID_NDX (ndx, Elf64_Rel, &data_scn->d))
 	{
 	  __libelf_seterrno (ELF_E_INVALID_INDEX);
 	  result = NULL;
--- a/libelf/gelf_getsym.c
+++ b/libelf/gelf_getsym.c
@@ -1,5 +1,5 @@
 /* Get symbol information from symbol table at the given index.
-   Copyright (C) 1999, 2000, 2001, 2002 Red Hat, Inc.
+   Copyright (C) 1999-2009 Red Hat, Inc.
    This file is part of elfutils.
    Written by Ulrich Drepper <drepper@redhat.com>, 1999.
 
@@ -69,7 +69,7 @@ gelf_getsym (data, ndx, dst)
 	 table entries has to be adopted.  The user better has provided
 	 a buffer where we can store the information.  While copying the
 	 data we are converting the format.  */
-      if (unlikely ((ndx + 1) * sizeof (Elf32_Sym) > data->d_size))
+      if (INVALID_NDX (ndx, Elf32_Sym, data))
 	{
 	  __libelf_seterrno (ELF_E_INVALID_INDEX);
 	  goto out;
@@ -98,7 +98,7 @@ gelf_getsym (data, ndx, dst)
 
       /* The data is already in the correct form.  Just make sure the
 	 index is OK.  */
-      if (unlikely ((ndx + 1) * sizeof (GElf_Sym) > data->d_size))
+      if (INVALID_NDX (ndx, GElf_Sym, data))
 	{
 	  __libelf_seterrno (ELF_E_INVALID_INDEX);
 	  goto out;
--- a/libelf/gelf_getsyminfo.c
+++ b/libelf/gelf_getsyminfo.c
@@ -1,5 +1,5 @@
 /* Get additional symbol information from symbol table at the given index.
-   Copyright (C) 2000, 2001, 2002 Red Hat, Inc.
+   Copyright (C) 2000-2009 Red Hat, Inc.
    This file is part of elfutils.
    Written by Ulrich Drepper <drepper@redhat.com>, 2000.
 
@@ -63,7 +63,7 @@ gelf_getsyminfo (data, ndx, dst)
 
   /* The data is already in the correct form.  Just make sure the
      index is OK.  */
-  if (unlikely ((ndx + 1) * sizeof (GElf_Syminfo) > data->d_size))
+  if (INVALID_NDX (ndx, GElf_Syminfo, data))
     {
       __libelf_seterrno (ELF_E_INVALID_INDEX);
       goto out;
--- a/libelf/gelf_getsymshndx.c
+++ b/libelf/gelf_getsymshndx.c
@@ -1,6 +1,6 @@
 /* Get symbol information and separate section index from symbol table
    at the given index.
-   Copyright (C) 2000, 2001, 2002 Red Hat, Inc.
+   Copyright (C) 2000-2009 Red Hat, Inc.
    This file is part of elfutils.
    Written by Ulrich Drepper <drepper@redhat.com>, 2000.
 
@@ -69,7 +69,7 @@ gelf_getsymshndx (symdata, shndxdata, nd
      section index table.  */
   if (likely (shndxdata_scn != NULL))
     {
-      if (unlikely ((ndx + 1) * sizeof (Elf32_Word) > shndxdata_scn->d.d_size))
+      if (INVALID_NDX (ndx, Elf32_Word, &shndxdata_scn->d))
 	{
 	  __libelf_seterrno (ELF_E_INVALID_INDEX);
 	  goto out;
@@ -89,7 +89,7 @@ gelf_getsymshndx (symdata, shndxdata, nd
 	 table entries has to be adopted.  The user better has provided
 	 a buffer where we can store the information.  While copying the
 	 data we are converting the format.  */
-      if (unlikely ((ndx + 1) * sizeof (Elf32_Sym) > symdata->d_size))
+      if (INVALID_NDX (ndx, Elf32_Sym, symdata))
 	{
 	  __libelf_seterrno (ELF_E_INVALID_INDEX);
 	  goto out;
@@ -118,7 +118,7 @@ gelf_getsymshndx (symdata, shndxdata, nd
 
       /* The data is already in the correct form.  Just make sure the
 	 index is OK.  */
-      if (unlikely ((ndx + 1) * sizeof (GElf_Sym) > symdata->d_size))
+      if (INVALID_NDX (ndx, GElf_Sym, symdata))
 	{
 	  __libelf_seterrno (ELF_E_INVALID_INDEX);
 	  goto out;
--- a/libelf/gelf_getversym.c
+++ b/libelf/gelf_getversym.c
@@ -1,5 +1,5 @@
 /* Get symbol version information at the given index.
-   Copyright (C) 1999, 2000, 2001, 2002 Red Hat, Inc.
+   Copyright (C) 1999-2009 Red Hat, Inc.
    This file is part of elfutils.
    Written by Ulrich Drepper <drepper@redhat.com>, 1999.
 
@@ -71,7 +71,7 @@ gelf_getversym (data, ndx, dst)
 
   /* The data is already in the correct form.  Just make sure the
      index is OK.  */
-  if (unlikely ((ndx + 1) * sizeof (GElf_Versym) > data->d_size))
+  if (INVALID_NDX (ndx, GElf_Versym, data))
     {
       __libelf_seterrno (ELF_E_INVALID_INDEX);
       result = NULL;
--- a/libelf/gelf_update_dyn.c
+++ b/libelf/gelf_update_dyn.c
@@ -1,5 +1,5 @@
 /* Update information in dynamic table at the given index.
-   Copyright (C) 2000, 2001, 2002 Red Hat, Inc.
+   Copyright (C) 2000-2009 Red Hat, Inc.
    This file is part of elfutils.
    Written by Ulrich Drepper <drepper@redhat.com>, 2000.
 
@@ -50,12 +50,6 @@ gelf_update_dyn (data, ndx, src)
   if (data == NULL)
     return 0;
 
-  if (unlikely (ndx < 0))
-    {
-      __libelf_seterrno (ELF_E_INVALID_INDEX);
-      return 0;
-    }
-
   if (unlikely (data_scn->d.d_type != ELF_T_DYN))
     {
       /* The type of the data better should match.  */
@@ -81,7 +75,7 @@ gelf_update_dyn (data, ndx, src)
 	}
 
       /* Check whether we have to resize the data buffer.  */
-      if (unlikely ((ndx + 1) * sizeof (Elf32_Dyn) > data_scn->d.d_size))
+      if (INVALID_NDX (ndx, Elf32_Dyn, &data_scn->d))
 	{
 	  __libelf_seterrno (ELF_E_INVALID_INDEX);
 	  goto out;
@@ -95,7 +89,7 @@ gelf_update_dyn (data, ndx, src)
   else
     {
       /* Check whether we have to resize the data buffer.  */
-      if (unlikely ((ndx + 1) * sizeof (Elf64_Dyn) > data_scn->d.d_size))
+      if (INVALID_NDX (ndx, Elf64_Dyn, &data_scn->d))
 	{
 	  __libelf_seterrno (ELF_E_INVALID_INDEX);
 	  goto out;
--- a/libelf/gelf_update_lib.c
+++ b/libelf/gelf_update_lib.c
@@ -1,5 +1,5 @@
 /* Update library in table at the given index.
-   Copyright (C) 2004 Red Hat, Inc.
+   Copyright (C) 2004-2009 Red Hat, Inc.
    This file is part of elfutils.
    Written by Ulrich Drepper <drepper@redhat.com>, 2004.
 
@@ -47,12 +47,6 @@ gelf_update_lib (data, ndx, src)
   if (data == NULL)
     return 0;
 
-  if (unlikely (ndx < 0))
-    {
-      __libelf_seterrno (ELF_E_INVALID_INDEX);
-      return 0;
-    }
-
   Elf_Data_Scn *data_scn = (Elf_Data_Scn *) data;
   if (unlikely (data_scn->d.d_type != ELF_T_LIB))
     {
@@ -66,7 +60,7 @@ gelf_update_lib (data, ndx, src)
 
   /* Check whether we have to resize the data buffer.  */
   int result = 0;
-  if (unlikely ((ndx + 1) * sizeof (Elf64_Lib) > data_scn->d.d_size))
+  if (INVALID_NDX (ndx, Elf64_Lib, &data_scn->d))
     __libelf_seterrno (ELF_E_INVALID_INDEX);
   else
     {
--- a/libelf/gelf_update_move.c
+++ b/libelf/gelf_update_move.c
@@ -1,5 +1,5 @@
 /* Update move structure at the given index.
-   Copyright (C) 2000, 2001, 2002 Red Hat, Inc.
+   Copyright (C) 2000-2009 Red Hat, Inc.
    This file is part of elfutils.
    Written by Ulrich Drepper <drepper@redhat.com>, 2000.
 
@@ -54,8 +54,7 @@ gelf_update_move (data, ndx, src)
   assert (sizeof (GElf_Move) == sizeof (Elf64_Move));
 
   /* Check whether we have to resize the data buffer.  */
-  if (unlikely (ndx < 0)
-      || unlikely ((ndx + 1) * sizeof (GElf_Move) > data_scn->d.d_size))
+  if (INVALID_NDX (ndx, GElf_Move, &data_scn->d))
     {
       __libelf_seterrno (ELF_E_INVALID_INDEX);
       return 0;
--- a/libelf/gelf_update_rela.c
+++ b/libelf/gelf_update_rela.c
@@ -1,5 +1,5 @@
 /* Update RELA relocation information at given index.
-   Copyright (C) 2000, 2001, 2002 Red Hat, Inc.
+   Copyright (C) 2000-2009 Red Hat, Inc.
    This file is part of elfutils.
    Written by Ulrich Drepper <drepper@redhat.com>, 2000.
 
@@ -47,12 +47,6 @@ gelf_update_rela (Elf_Data *dst, int ndx
   if (dst == NULL)
     return 0;
 
-  if (unlikely (ndx < 0))
-    {
-      __libelf_seterrno (ELF_E_INVALID_INDEX);
-      return 0;
-    }
-
   if (unlikely (data_scn->d.d_type != ELF_T_RELA))
     {
       /* The type of the data better should match.  */
@@ -80,7 +74,7 @@ gelf_update_rela (Elf_Data *dst, int ndx
 	}
 
       /* Check whether we have to resize the data buffer.  */
-      if (unlikely ((ndx + 1) * sizeof (Elf32_Rela) > data_scn->d.d_size))
+      if (INVALID_NDX (ndx, Elf32_Rela, &data_scn->d))
 	{
 	  __libelf_seterrno (ELF_E_INVALID_INDEX);
 	  goto out;
@@ -96,7 +90,7 @@ gelf_update_rela (Elf_Data *dst, int ndx
   else
     {
       /* Check whether we have to resize the data buffer.  */
-      if (unlikely ((ndx + 1) * sizeof (Elf64_Rela) > data_scn->d.d_size))
+      if (INVALID_NDX (ndx, Elf64_Rela, &data_scn->d))
 	{
 	  __libelf_seterrno (ELF_E_INVALID_INDEX);
 	  goto out;
--- a/libelf/gelf_update_rel.c
+++ b/libelf/gelf_update_rel.c
@@ -1,5 +1,5 @@
 /* Update REL relocation information at given index.
-   Copyright (C) 2000, 2001, 2002 Red Hat, Inc.
+   Copyright (C) 2000-2009 Red Hat, Inc.
    This file is part of elfutils.
    Written by Ulrich Drepper <drepper@redhat.com>, 2000.
 
@@ -47,12 +47,6 @@ gelf_update_rel (Elf_Data *dst, int ndx,
   if (dst == NULL)
     return 0;
 
-  if (unlikely (ndx < 0))
-    {
-      __libelf_seterrno (ELF_E_INVALID_INDEX);
-      return 0;
-    }
-
   if (unlikely (data_scn->d.d_type != ELF_T_REL))
     {
       /* The type of the data better should match.  */
@@ -78,7 +72,7 @@ gelf_update_rel (Elf_Data *dst, int ndx,
 	}
 
       /* Check whether we have to resize the data buffer.  */
-      if (unlikely ((ndx + 1) * sizeof (Elf32_Rel) > data_scn->d.d_size))
+      if (INVALID_NDX (ndx, Elf32_Rel, &data_scn->d))
 	{
 	  __libelf_seterrno (ELF_E_INVALID_INDEX);
 	  goto out;
@@ -93,7 +87,7 @@ gelf_update_rel (Elf_Data *dst, int ndx,
   else
     {
       /* Check whether we have to resize the data buffer.  */
-      if (unlikely ((ndx + 1) * sizeof (Elf64_Rel) > data_scn->d.d_size))
+      if (INVALID_NDX (ndx, Elf64_Rel, &data_scn->d))
 	{
 	  __libelf_seterrno (ELF_E_INVALID_INDEX);
 	  goto out;
--- a/libelf/gelf_update_sym.c
+++ b/libelf/gelf_update_sym.c
@@ -1,5 +1,5 @@
 /* Update symbol information in symbol table at the given index.
-   Copyright (C) 2000, 2001, 2002 Red Hat, Inc.
+   Copyright (C) 2000-2009 Red Hat, Inc.
    This file is part of elfutils.
    Written by Ulrich Drepper <drepper@redhat.com>, 2000.
 
@@ -51,12 +51,6 @@ gelf_update_sym (data, ndx, src)
   if (data == NULL)
     return 0;
 
-  if (unlikely (ndx < 0))
-    {
-      __libelf_seterrno (ELF_E_INVALID_INDEX);
-      return 0;
-    }
-
   if (unlikely (data_scn->d.d_type != ELF_T_SYM))
     {
       /* The type of the data better should match.  */
@@ -81,7 +75,7 @@ gelf_update_sym (data, ndx, src)
 	}
 
       /* Check whether we have to resize the data buffer.  */
-      if (unlikely ((ndx + 1) * sizeof (Elf32_Sym) > data_scn->d.d_size))
+      if (INVALID_NDX (ndx, Elf32_Sym, &data_scn->d))
 	{
 	  __libelf_seterrno (ELF_E_INVALID_INDEX);
 	  goto out;
@@ -104,7 +98,7 @@ gelf_update_sym (data, ndx, src)
   else
     {
       /* Check whether we have to resize the data buffer.  */
-      if (unlikely ((ndx + 1) * sizeof (Elf64_Sym) > data_scn->d.d_size))
+      if (INVALID_NDX (ndx, Elf64_Sym, &data_scn->d))
 	{
 	  __libelf_seterrno (ELF_E_INVALID_INDEX);
 	  goto out;
--- a/libelf/gelf_update_syminfo.c
+++ b/libelf/gelf_update_syminfo.c
@@ -1,5 +1,5 @@
 /* Update additional symbol information in symbol table at the given index.
-   Copyright (C) 2000, 2001, 2002 Red Hat, Inc.
+   Copyright (C) 2000-2009 Red Hat, Inc.
    This file is part of elfutils.
    Written by Ulrich Drepper <drepper@redhat.com>, 2000.
 
@@ -51,12 +51,6 @@ gelf_update_syminfo (data, ndx, src)
   if (data == NULL)
     return 0;
 
-  if (unlikely (ndx < 0))
-    {
-      __libelf_seterrno (ELF_E_INVALID_INDEX);
-      return 0;
-    }
-
   if (unlikely (data_scn->d.d_type != ELF_T_SYMINFO))
     {
       /* The type of the data better should match.  */
@@ -72,7 +66,7 @@ gelf_update_syminfo (data, ndx, src)
   rwlock_wrlock (scn->elf->lock);
 
   /* Check whether we have to resize the data buffer.  */
-  if (unlikely ((ndx + 1) * sizeof (GElf_Syminfo) > data_scn->d.d_size))
+  if (INVALID_NDX (ndx, GElf_Syminfo, &data_scn->d))
     {
       __libelf_seterrno (ELF_E_INVALID_INDEX);
       goto out;
--- a/libelf/gelf_update_symshndx.c
+++ b/libelf/gelf_update_symshndx.c
@@ -1,6 +1,6 @@
 /* Update symbol information and section index in symbol table at the
    given index.
-   Copyright (C) 2000, 2001, 2002 Red Hat, Inc.
+   Copyright (C) 2000-2009 Red Hat, Inc.
    This file is part of elfutils.
    Written by Ulrich Drepper <drepper@redhat.com>, 2000.
 
@@ -56,12 +56,6 @@ gelf_update_symshndx (symdata, shndxdata
   if (symdata == NULL)
     return 0;
 
-  if (unlikely (ndx < 0))
-    {
-      __libelf_seterrno (ELF_E_INVALID_INDEX);
-      return 0;
-    }
-
   if (unlikely (symdata_scn->d.d_type != ELF_T_SYM))
     {
       /* The type of the data better should match.  */
@@ -107,7 +101,7 @@ gelf_update_symshndx (symdata, shndxdata
 	}
 
       /* Check whether we have to resize the data buffer.  */
-      if (unlikely ((ndx + 1) * sizeof (Elf32_Sym) > symdata_scn->d.d_size))
+      if (INVALID_NDX (ndx, Elf32_Sym, &symdata_scn->d))
 	{
 	  __libelf_seterrno (ELF_E_INVALID_INDEX);
 	  goto out;
@@ -130,7 +124,7 @@ gelf_update_symshndx (symdata, shndxdata
   else
     {
       /* Check whether we have to resize the data buffer.  */
-      if (unlikely ((ndx + 1) * sizeof (Elf64_Sym) > symdata_scn->d.d_size))
+      if (INVALID_NDX (ndx, Elf64_Sym, &symdata_scn->d))
 	{
 	  __libelf_seterrno (ELF_E_INVALID_INDEX);
 	  goto out;
--- a/libelf/gelf_update_versym.c
+++ b/libelf/gelf_update_versym.c
@@ -1,5 +1,5 @@
 /* Update symbol version information.
-   Copyright (C) 2001, 2002 Red Hat, Inc.
+   Copyright (C) 2001-2009 Red Hat, Inc.
    This file is part of elfutils.
    Written by Ulrich Drepper <drepper@redhat.com>, 2001.
 
@@ -54,8 +54,7 @@ gelf_update_versym (data, ndx, src)
   assert (sizeof (GElf_Versym) == sizeof (Elf64_Versym));
 
   /* Check whether we have to resize the data buffer.  */
-  if (unlikely (ndx < 0)
-      || unlikely ((ndx + 1) * sizeof (GElf_Versym) > data_scn->d.d_size))
+  if (INVALID_NDX (ndx, GElf_Versym, &data_scn->d))
     {
       __libelf_seterrno (ELF_E_INVALID_INDEX);
       return 0;
--- a/libelf/libelfP.h
+++ b/libelf/libelfP.h
@@ -587,4 +587,8 @@ extern uint32_t __libelf_crc32 (uint32_t
 /* Align offset to 4 bytes as needed for note name and descriptor data.  */
 #define NOTE_ALIGN(n)	(((n) + 3) & -4U)
 
+/* Convenience macro.  */
+#define INVALID_NDX(ndx, type, data) \
+  unlikely ((data)->d_size / sizeof (type) <= (unsigned int) (ndx))
+
 #endif  /* libelfP.h */
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -702,6 +702,12 @@
 
 	* readelf.c (dwarf_attr_string): Grok DW_AT_GNU_odr_signature.
 
+2011-03-23  Petr Machata  <pmachata@redhat.com>
+
+	* readelf.c (handle_dynamic, handle_relocs_rel)
+	(handle_relocs_rela, handle_versym, print_liblist):
+	Use gelf_fsize instead of relying on shdr->sh_entsize.
+
 2011-02-11  Roland McGrath  <roland@redhat.com>
 
 	* elfcmp.c (verbose): New variable.
@@ -2439,6 +2445,16 @@
 	object symbols or symbols with unknown type.
 	(check_rel): Likewise.
 
+2005-06-09  Roland McGrath  <roland@redhat.com>
+
+	* readelf.c (handle_dynamic, handle_symtab): Check for bogus sh_link.
+	(handle_verneed, handle_verdef, handle_versym, handle_hash): Likewise.
+	(handle_scngrp): Check for bogus sh_info.
+
+	* strip.c (handle_elf): Check for bogus values in sh_link, sh_info,
+	st_shndx, e_shstrndx, and SHT_GROUP or SHT_SYMTAB_SHNDX data.
+	Don't use assert on input values, instead bail with "illformed" error.
+
 2005-06-08  Roland McGrath  <roland@redhat.com>
 
 	* readelf.c (print_ops): Add consts.
@@ -2489,6 +2505,19 @@
 
 	* readelf.c (dwarf_tag_string): Add new tags.
 
+2005-05-17  Jakub Jelinek  <jakub@redhat.com>
+
+	* elflint.c (check_hash): Don't check entries beyond end of section.
+	(check_note): Don't crash if gelf_rawchunk fails.
+	(section_name): Return <invalid> if gelf_getshdr returns NULL.
+
+2005-05-14  Jakub Jelinek  <jakub@redhat.com>
+
+	* elflint.c (section_name): Return "<invalid>" instead of
+	crashing on invalid section name.
+	(check_symtab, is_rel_dyn, check_rela, check_rel, check_dynamic,
+	check_symtab_shndx, check_hash, check_versym): Robustify.
+
 2005-05-08  Roland McGrath  <roland@redhat.com>
 
 	* strip.c (handle_elf): Don't translate hash and versym data formats,
--- a/src/elflint.c
+++ b/src/elflint.c
@@ -123,6 +123,10 @@ static uint32_t shstrndx;
 /* Array to count references in section groups.  */
 static int *scnref;
 
+/* Numbers of sections and program headers.  */
+static unsigned int shnum;
+static unsigned int phnum;
+
 
 int
 main (int argc, char *argv[])
@@ -311,10 +315,19 @@ section_name (Ebl *ebl, int idx)
 {
   GElf_Shdr shdr_mem;
   GElf_Shdr *shdr;
+  const char *ret;
+
+  if ((unsigned int) idx > shnum)
+    return "<invalid>";
 
   shdr = gelf_getshdr (elf_getscn (ebl->elf, idx), &shdr_mem);
+  if (shdr == NULL)
+    return "<invalid>";
 
-  return elf_strptr (ebl->elf, shstrndx, shdr->sh_name);
+  ret = elf_strptr (ebl->elf, shstrndx, shdr->sh_name);
+  if (ret == NULL)
+    return "<invalid>";
+  return ret;
 }
 
 
@@ -337,11 +350,6 @@ static const int valid_e_machine[] =
   (sizeof (valid_e_machine) / sizeof (valid_e_machine[0]))
 
 
-/* Numbers of sections and program headers.  */
-static unsigned int shnum;
-static unsigned int phnum;
-
-
 static void
 check_elf_header (Ebl *ebl, GElf_Ehdr *ehdr, size_t size)
 {
@@ -625,7 +633,8 @@ section [%2d] '%s': symbol table cannot
 	  }
       }
 
-  if (shdr->sh_entsize != gelf_fsize (ebl->elf, ELF_T_SYM, 1, EV_CURRENT))
+  size_t sh_entsize = gelf_fsize (ebl->elf, ELF_T_SYM, 1, EV_CURRENT);
+  if (shdr->sh_entsize != sh_entsize)
     ERROR (gettext ("\
 section [%2u] '%s': entry size is does not match ElfXX_Sym\n"),
 	   idx, section_name (ebl, idx));
@@ -663,7 +672,7 @@ section [%2d] '%s': XINDEX for zeroth en
 	       xndxscnidx, section_name (ebl, xndxscnidx));
     }
 
-  for (size_t cnt = 1; cnt < shdr->sh_size / shdr->sh_entsize; ++cnt)
+  for (size_t cnt = 1; cnt < shdr->sh_size / sh_entsize; ++cnt)
     {
       sym = gelf_getsymshndx (data, xndxdata, cnt, &sym_mem, &xndx);
       if (sym == NULL)
@@ -683,7 +692,8 @@ section [%2d] '%s': symbol %zu: invalid
       else
 	{
 	  name = elf_strptr (ebl->elf, shdr->sh_link, sym->st_name);
-	  assert (name != NULL);
+	  assert (name != NULL
+		  || strshdr->sh_type != SHT_STRTAB);
 	}
 
       if (sym->st_shndx == SHN_XINDEX)
@@ -1040,9 +1050,11 @@ is_rel_dyn (Ebl *ebl, const GElf_Ehdr *e
     {
       GElf_Shdr rcshdr_mem;
       const GElf_Shdr *rcshdr = gelf_getshdr (scn, &rcshdr_mem);
-      assert (rcshdr != NULL);
 
-      if (rcshdr->sh_type == SHT_DYNAMIC)
+      if (rcshdr == NULL)
+	break;
+
+      if (rcshdr->sh_type == SHT_DYNAMIC && rcshdr->sh_entsize)
 	{
 	  /* Found the dynamic section.  Look through it.  */
 	  Elf_Data *d = elf_getdata (scn, NULL);
@@ -1052,7 +1064,9 @@ is_rel_dyn (Ebl *ebl, const GElf_Ehdr *e
 	    {
 	      GElf_Dyn dyn_mem;
 	      GElf_Dyn *dyn = gelf_getdyn (d, cnt, &dyn_mem);
-	      assert (dyn != NULL);
+
+	      if (dyn == NULL)
+		break;
 
 	      if (dyn->d_tag == DT_RELCOUNT)
 		{
@@ -1066,7 +1080,9 @@ section [%2d] '%s': DT_RELCOUNT used for
 		      /* Does the number specified number of relative
 			 relocations exceed the total number of
 			 relocations?  */
-		      if (dyn->d_un.d_val > shdr->sh_size / shdr->sh_entsize)
+		      if (shdr->sh_entsize != 0
+			  && dyn->d_un.d_val > (shdr->sh_size
+						/ shdr->sh_entsize))
 			ERROR (gettext ("\
 section [%2d] '%s': DT_RELCOUNT value %d too high for this section\n"),
 			       idx, section_name (ebl, idx),
@@ -1226,7 +1242,8 @@ section [%2d] '%s': no relocations for m
 	}
     }
 
-  if (shdr->sh_entsize != gelf_fsize (ebl->elf, reltype, 1, EV_CURRENT))
+  size_t sh_entsize = gelf_fsize (ebl->elf, reltype, 1, EV_CURRENT);
+  if (shdr->sh_entsize != sh_entsize)
     ERROR (gettext (reltype == ELF_T_RELA ? "\
 section [%2d] '%s': section entry size does not match ElfXX_Rela\n" : "\
 section [%2d] '%s': section entry size does not match ElfXX_Rel\n"),
@@ -1449,7 +1466,8 @@ check_rela (Ebl *ebl, GElf_Ehdr *ehdr, G
   Elf_Data *symdata = elf_getdata (symscn, NULL);
   enum load_state state = state_undecided;
 
-  for (size_t cnt = 0; cnt < shdr->sh_size / shdr->sh_entsize; ++cnt)
+  size_t sh_entsize = gelf_fsize (ebl->elf, ELF_T_RELA, 1, EV_CURRENT);
+  for (size_t cnt = 0; cnt < shdr->sh_size / sh_entsize; ++cnt)
     {
       GElf_Rela rela_mem;
       GElf_Rela *rela = gelf_getrela (data, cnt, &rela_mem);
@@ -1499,7 +1517,8 @@ check_rel (Ebl *ebl, GElf_Ehdr *ehdr, GE
   Elf_Data *symdata = elf_getdata (symscn, NULL);
   enum load_state state = state_undecided;
 
-  for (size_t cnt = 0; cnt < shdr->sh_size / shdr->sh_entsize; ++cnt)
+  size_t sh_entsize = gelf_fsize (ebl->elf, ELF_T_REL, 1, EV_CURRENT);
+  for (size_t cnt = 0; cnt < shdr->sh_size / sh_entsize; ++cnt)
     {
       GElf_Rel rel_mem;
       GElf_Rel *rel = gelf_getrel (data, cnt, &rel_mem);
@@ -1598,7 +1617,8 @@ section [%2d] '%s': referenced as string
 	   shdr->sh_link, section_name (ebl, shdr->sh_link),
 	   idx, section_name (ebl, idx));
 
-  if (shdr->sh_entsize != gelf_fsize (ebl->elf, ELF_T_DYN, 1, EV_CURRENT))
+  size_t sh_entsize = gelf_fsize (ebl->elf, ELF_T_DYN, 1, EV_CURRENT);
+  if (shdr->sh_entsize != sh_entsize)
     ERROR (gettext ("\
 section [%2d] '%s': section entry size does not match ElfXX_Dyn\n"),
 	   idx, section_name (ebl, idx));
@@ -1608,7 +1628,7 @@ section [%2d] '%s': section entry size d
 	   idx, section_name (ebl, idx));
 
   bool non_null_warned = false;
-  for (cnt = 0; cnt < shdr->sh_size / shdr->sh_entsize; ++cnt)
+  for (cnt = 0; cnt < shdr->sh_size / sh_entsize; ++cnt)
     {
       GElf_Dyn dyn_mem;
       GElf_Dyn *dyn = gelf_getdyn (data, cnt, &dyn_mem);
@@ -1880,6 +1900,8 @@ section [%2d] '%s': entry size does not
 	   idx, section_name (ebl, idx));
 
   if (symshdr != NULL
+      && shdr->sh_entsize
+      && symshdr->sh_entsize
       && (shdr->sh_size / shdr->sh_entsize
 	  < symshdr->sh_size / symshdr->sh_entsize))
     ERROR (gettext ("\
@@ -1906,6 +1928,12 @@ section [%2d] '%s': extended section ind
     }
 
   Elf_Data *data = elf_getdata (elf_getscn (ebl->elf, idx), NULL);
+  if (data == NULL)
+    {
+      ERROR (gettext ("section [%2d] '%s': cannot get section data\n"),
+ 	     idx, section_name (ebl, idx));
+      return;
+    }
 
   if (*((Elf32_Word *) data->d_buf) != 0)
     ERROR (gettext ("symbol 0 should have zero extended section index\n"));
@@ -1948,7 +1976,7 @@ section [%2d] '%s': hash table section i
 
   size_t maxidx = nchain;
 
-  if (symshdr != NULL)
+  if (symshdr != NULL && symshdr->sh_entsize != 0)
     {
       size_t symsize = symshdr->sh_size / symshdr->sh_entsize;
 
@@ -1959,18 +1987,28 @@ section [%2d] '%s': hash table section i
       maxidx = symsize;
     }
 
+  Elf32_Word *buf = (Elf32_Word *) data->d_buf;
+  Elf32_Word *end = (Elf32_Word *) ((char *) data->d_buf + shdr->sh_size);
   size_t cnt;
   for (cnt = 2; cnt < 2 + nbucket; ++cnt)
-    if (((Elf32_Word *) data->d_buf)[cnt] >= maxidx)
+    {
+      if (buf + cnt >= end)
+	break;
+      else if (buf[cnt] >= maxidx)
       ERROR (gettext ("\
 section [%2d] '%s': hash bucket reference %zu out of bounds\n"),
 	     idx, section_name (ebl, idx), cnt - 2);
+    }
 
   for (; cnt < 2 + nbucket + nchain; ++cnt)
-    if (((Elf32_Word *) data->d_buf)[cnt] >= maxidx)
+    {
+      if (buf + cnt >= end)
+	break;
+      else if (buf[cnt] >= maxidx)
       ERROR (gettext ("\
 section [%2d] '%s': hash chain reference %zu out of bounds\n"),
 	     idx, section_name (ebl, idx), cnt - 2 - nbucket);
+    }
 }
 
 
@@ -2000,18 +2038,28 @@ section [%2d] '%s': hash table section i
       maxidx = symsize;
     }
 
+  Elf64_Xword *buf = (Elf64_Xword *) data->d_buf;
+  Elf64_Xword *end = (Elf64_Xword *) ((char *) data->d_buf + shdr->sh_size);
   size_t cnt;
   for (cnt = 2; cnt < 2 + nbucket; ++cnt)
-    if (((Elf64_Xword *) data->d_buf)[cnt] >= maxidx)
+    {
+      if (buf + cnt >= end)
+	break;
+      else if (buf[cnt] >= maxidx)
       ERROR (gettext ("\
 section [%2d] '%s': hash bucket reference %zu out of bounds\n"),
 	     idx, section_name (ebl, idx), cnt - 2);
+    }
 
   for (; cnt < 2 + nbucket + nchain; ++cnt)
-    if (((Elf64_Xword *) data->d_buf)[cnt] >= maxidx)
+    {
+      if (buf + cnt >= end)
+	break;
+      else if (buf[cnt] >= maxidx)
       ERROR (gettext ("\
 section [%2d] '%s': hash chain reference %" PRIu64 " out of bounds\n"),
-	     idx, section_name (ebl, idx), (uint64_t) (cnt - 2 - nbucket));
+	       idx, section_name (ebl, idx), (uint64_t) cnt - 2 - nbucket);
+    }
 }
 
 
@@ -2036,7 +2084,7 @@ section [%2d] '%s': bitmask size not pow
   if (shdr->sh_size < (4 + bitmask_words + nbuckets) * sizeof (Elf32_Word))
     {
       ERROR (gettext ("\
-section [%2d] '%s': hash table section is too small (is %ld, expected at least%ld)\n"),
+section [%2d] '%s': hash table section is too small (is %ld, expected at least %ld)\n"),
 	     idx, section_name (ebl, idx), (long int) shdr->sh_size,
 	     (long int) ((4 + bitmask_words + nbuckets) * sizeof (Elf32_Word)));
       return;
@@ -2708,8 +2756,9 @@ section [%2d] '%s' refers in sh_link to
 
   /* The number of elements in the version symbol table must be the
      same as the number of symbols.  */
-  if (shdr->sh_size / shdr->sh_entsize
-      != symshdr->sh_size / symshdr->sh_entsize)
+  if (shdr->sh_entsize && symshdr->sh_entsize
+      && (shdr->sh_size / shdr->sh_entsize
+	  != symshdr->sh_size / symshdr->sh_entsize))
     ERROR (gettext ("\
 section [%2d] '%s' has different number of entries than symbol table [%2d] '%s'\n"),
 	   idx, section_name (ebl, idx),
--- a/src/readelf.c
+++ b/src/readelf.c
@@ -1364,6 +1364,8 @@ handle_scngrp (Ebl *ebl, Elf_Scn *scn, G
   Elf32_Word *grpref = (Elf32_Word *) data->d_buf;
 
   GElf_Sym sym_mem;
+  GElf_Sym *sym = gelf_getsym (symdata, shdr->sh_info, &sym_mem);
+
   printf ((grpref[0] & GRP_COMDAT)
 	  ? ngettext ("\
 \nCOMDAT section group [%2zu] '%s' with signature '%s' contains %zu entry:\n",
@@ -1376,8 +1378,8 @@ handle_scngrp (Ebl *ebl, Elf_Scn *scn, G
 		      data->d_size / sizeof (Elf32_Word) - 1),
 	  elf_ndxscn (scn),
 	  elf_strptr (ebl->elf, shstrndx, shdr->sh_name),
-	  elf_strptr (ebl->elf, symshdr->sh_link,
-		      gelf_getsym (symdata, shdr->sh_info, &sym_mem)->st_name)
+	  (sym == NULL ? NULL
+	   : elf_strptr (ebl->elf, symshdr->sh_link, sym->st_name))
 	  ?: gettext ("<INVALID SYMBOL>"),
 	  data->d_size / sizeof (Elf32_Word) - 1);
 
@@ -1528,10 +1530,12 @@ static void
 handle_dynamic (Ebl *ebl, Elf_Scn *scn, GElf_Shdr *shdr)
 {
   int class = gelf_getclass (ebl->elf);
-  GElf_Shdr glink;
+  GElf_Shdr glink_mem;
+  GElf_Shdr *glink;
   Elf_Data *data;
   size_t cnt;
   size_t shstrndx;
+  size_t sh_entsize;
 
   /* Get the data of the section.  */
   data = elf_getdata (scn, NULL);
@@ -1543,21 +1547,26 @@ handle_dynamic (Ebl *ebl, Elf_Scn *scn,
     error (EXIT_FAILURE, 0,
 	   gettext ("cannot get section header string table index"));
 
+  sh_entsize = gelf_fsize (ebl->elf, ELF_T_DYN, 1, EV_CURRENT);
+
+  glink = gelf_getshdr (elf_getscn (ebl->elf, shdr->sh_link), &glink_mem);
+  if (glink == NULL)
+    error (EXIT_FAILURE, 0, gettext ("invalid sh_link value in section %Zu"),
+	   elf_ndxscn (scn));
+
   printf (ngettext ("\
 \nDynamic segment contains %lu entry:\n Addr: %#0*" PRIx64 "  Offset: %#08" PRIx64 "  Link to section: [%2u] '%s'\n",
 		    "\
 \nDynamic segment contains %lu entries:\n Addr: %#0*" PRIx64 "  Offset: %#08" PRIx64 "  Link to section: [%2u] '%s'\n",
-		    shdr->sh_size / shdr->sh_entsize),
-	  (unsigned long int) (shdr->sh_size / shdr->sh_entsize),
+		    shdr->sh_size / sh_entsize),
+	  (unsigned long int) (shdr->sh_size / sh_entsize),
 	  class == ELFCLASS32 ? 10 : 18, shdr->sh_addr,
 	  shdr->sh_offset,
 	  (int) shdr->sh_link,
-	  elf_strptr (ebl->elf, shstrndx,
-		      gelf_getshdr (elf_getscn (ebl->elf, shdr->sh_link),
-				    &glink)->sh_name));
+	  elf_strptr (ebl->elf, shstrndx, glink->sh_name));
   fputs_unlocked (gettext ("  Type              Value\n"), stdout);
 
-  for (cnt = 0; cnt < shdr->sh_size / shdr->sh_entsize; ++cnt)
+  for (cnt = 0; cnt < shdr->sh_size / sh_entsize; ++cnt)
     {
       GElf_Dyn dynmem;
       GElf_Dyn *dyn = gelf_getdyn (data, cnt, &dynmem);
@@ -1706,7 +1715,8 @@ static void
 handle_relocs_rel (Ebl *ebl, GElf_Ehdr *ehdr, Elf_Scn *scn, GElf_Shdr *shdr)
 {
   int class = gelf_getclass (ebl->elf);
-  int nentries = shdr->sh_size / shdr->sh_entsize;
+  size_t sh_entsize = gelf_fsize (ebl->elf, ELF_T_REL, 1, EV_CURRENT);
+  int nentries = shdr->sh_size / sh_entsize;
 
   /* Get the data of the section.  */
   Elf_Data *data = elf_getdata (scn, NULL);
@@ -1892,7 +1902,8 @@ static void
 handle_relocs_rela (Ebl *ebl, GElf_Ehdr *ehdr, Elf_Scn *scn, GElf_Shdr *shdr)
 {
   int class = gelf_getclass (ebl->elf);
-  int nentries = shdr->sh_size / shdr->sh_entsize;
+  size_t sh_entsize = gelf_fsize (ebl->elf, ELF_T_RELA, 1, EV_CURRENT);
+  int nentries = shdr->sh_size / sh_entsize;
 
   /* Get the data of the section.  */
   Elf_Data *data = elf_getdata (scn, NULL);
@@ -2139,6 +2150,13 @@ handle_symtab (Ebl *ebl, Elf_Scn *scn, G
     error (EXIT_FAILURE, 0,
 	   gettext ("cannot get section header string table index"));
 
+  GElf_Shdr glink_mem;
+  GElf_Shdr *glink = gelf_getshdr (elf_getscn (ebl->elf, shdr->sh_link),
+				   &glink_mem);
+  if (glink == NULL)
+    error (EXIT_FAILURE, 0, gettext ("invalid sh_link value in section %Zu"),
+	   elf_ndxscn (scn));
+
   /* Now we can compute the number of entries in the section.  */
   unsigned int nsyms = data->d_size / (class == ELFCLASS32
 				       ? sizeof (Elf32_Sym)
@@ -2149,15 +2167,12 @@ handle_symtab (Ebl *ebl, Elf_Scn *scn, G
 		    nsyms),
 	  (unsigned int) elf_ndxscn (scn),
 	  elf_strptr (ebl->elf, shstrndx, shdr->sh_name), nsyms);
-  GElf_Shdr glink;
   printf (ngettext (" %lu local symbol  String table: [%2u] '%s'\n",
 		    " %lu local symbols  String table: [%2u] '%s'\n",
 		    shdr->sh_info),
 	  (unsigned long int) shdr->sh_info,
 	  (unsigned int) shdr->sh_link,
-	  elf_strptr (ebl->elf, shstrndx,
-		      gelf_getshdr (elf_getscn (ebl->elf, shdr->sh_link),
-				    &glink)->sh_name));
+	  elf_strptr (ebl->elf, shstrndx, glink->sh_name));
 
   fputs_unlocked (class == ELFCLASS32
 		  ? gettext ("\
@@ -2393,7 +2408,13 @@ handle_verneed (Ebl *ebl, Elf_Scn *scn,
     error (EXIT_FAILURE, 0,
 	   gettext ("cannot get section header string table index"));
 
-  GElf_Shdr glink;
+  GElf_Shdr glink_mem;
+  GElf_Shdr *glink = gelf_getshdr (elf_getscn (ebl->elf, shdr->sh_link),
+				   &glink_mem);
+  if (glink == NULL)
+    error (EXIT_FAILURE, 0, gettext ("invalid sh_link value in section %Zu"),
+	   elf_ndxscn (scn));
+
   printf (ngettext ("\
 \nVersion needs section [%2u] '%s' contains %d entry:\n Addr: %#0*" PRIx64 "  Offset: %#08" PRIx64 "  Link to section: [%2u] '%s'\n",
 		    "\
@@ -2404,9 +2425,7 @@ handle_verneed (Ebl *ebl, Elf_Scn *scn,
 	  class == ELFCLASS32 ? 10 : 18, shdr->sh_addr,
 	  shdr->sh_offset,
 	  (unsigned int) shdr->sh_link,
-	  elf_strptr (ebl->elf, shstrndx,
-		      gelf_getshdr (elf_getscn (ebl->elf, shdr->sh_link),
-				    &glink)->sh_name));
+	  elf_strptr (ebl->elf, shstrndx, glink->sh_name));
 
   unsigned int offset = 0;
   for (int cnt = shdr->sh_info; --cnt >= 0; )
@@ -2459,8 +2478,14 @@ handle_verdef (Ebl *ebl, Elf_Scn *scn, G
     error (EXIT_FAILURE, 0,
 	   gettext ("cannot get section header string table index"));
 
+  GElf_Shdr glink_mem;
+  GElf_Shdr *glink = gelf_getshdr (elf_getscn (ebl->elf, shdr->sh_link),
+				   &glink_mem);
+  if (glink == NULL)
+    error (EXIT_FAILURE, 0, gettext ("invalid sh_link value in section %Zu"),
+	   elf_ndxscn (scn));
+
   int class = gelf_getclass (ebl->elf);
-  GElf_Shdr glink;
   printf (ngettext ("\
 \nVersion definition section [%2u] '%s' contains %d entry:\n Addr: %#0*" PRIx64 "  Offset: %#08" PRIx64 "  Link to section: [%2u] '%s'\n",
 		    "\
@@ -2472,9 +2497,7 @@ handle_verdef (Ebl *ebl, Elf_Scn *scn, G
 	  class == ELFCLASS32 ? 10 : 18, shdr->sh_addr,
 	  shdr->sh_offset,
 	  (unsigned int) shdr->sh_link,
-	  elf_strptr (ebl->elf, shstrndx,
-		      gelf_getshdr (elf_getscn (ebl->elf, shdr->sh_link),
-				    &glink)->sh_name));
+	  elf_strptr (ebl->elf, shstrndx, glink->sh_name));
 
   unsigned int offset = 0;
   for (int cnt = shdr->sh_info; --cnt >= 0; )
@@ -2736,25 +2759,30 @@ handle_versym (Ebl *ebl, Elf_Scn *scn, G
       filename = NULL;
     }
 
+  GElf_Shdr glink_mem;
+  GElf_Shdr *glink = gelf_getshdr (elf_getscn (ebl->elf, shdr->sh_link),
+				   &glink_mem);
+  size_t sh_entsize = gelf_fsize (ebl->elf, ELF_T_HALF, 1, EV_CURRENT);
+  if (glink == NULL)
+    error (EXIT_FAILURE, 0, gettext ("invalid sh_link value in section %Zu"),
+	   elf_ndxscn (scn));
+
   /* Print the header.  */
-  GElf_Shdr glink;
   printf (ngettext ("\
 \nVersion symbols section [%2u] '%s' contains %d entry:\n Addr: %#0*" PRIx64 "  Offset: %#08" PRIx64 "  Link to section: [%2u] '%s'",
 		    "\
 \nVersion symbols section [%2u] '%s' contains %d entries:\n Addr: %#0*" PRIx64 "  Offset: %#08" PRIx64 "  Link to section: [%2u] '%s'",
-		    shdr->sh_size / shdr->sh_entsize),
+		    shdr->sh_size / sh_entsize),
 	  (unsigned int) elf_ndxscn (scn),
 	  elf_strptr (ebl->elf, shstrndx, shdr->sh_name),
-	  (int) (shdr->sh_size / shdr->sh_entsize),
+	  (int) (shdr->sh_size / sh_entsize),
 	  class == ELFCLASS32 ? 10 : 18, shdr->sh_addr,
 	  shdr->sh_offset,
 	  (unsigned int) shdr->sh_link,
-	  elf_strptr (ebl->elf, shstrndx,
-		      gelf_getshdr (elf_getscn (ebl->elf, shdr->sh_link),
-				    &glink)->sh_name));
+	  elf_strptr (ebl->elf, shstrndx, glink->sh_name));
 
   /* Now we can finally look at the actual contents of this section.  */
-  for (unsigned int cnt = 0; cnt < shdr->sh_size / shdr->sh_entsize; ++cnt)
+  for (unsigned int cnt = 0; cnt < shdr->sh_size / sh_entsize; ++cnt)
     {
       if (cnt % 2 == 0)
 	printf ("\n %4d:", cnt);
@@ -2803,7 +2831,17 @@ print_hash_info (Ebl *ebl, Elf_Scn *scn,
   for (Elf32_Word cnt = 0; cnt < nbucket; ++cnt)
     ++counts[lengths[cnt]];
 
-  GElf_Shdr glink;
+  GElf_Shdr glink_mem;
+  GElf_Shdr *glink = gelf_getshdr (elf_getscn (ebl->elf,
+					       shdr->sh_link),
+				   &glink_mem);
+  if (glink == NULL)
+    {
+      error (0, 0, gettext ("invalid sh_link value in section %Zu"),
+	     elf_ndxscn (scn));
+      return;
+    }
+
   printf (ngettext ("\
 \nHistogram for bucket list length in section [%2u] '%s' (total of %d bucket):\n Addr: %#0*" PRIx64 "  Offset: %#08" PRIx64 "  Link to section: [%2u] '%s'\n",
 		    "\
@@ -2816,9 +2854,7 @@ print_hash_info (Ebl *ebl, Elf_Scn *scn,
 	  shdr->sh_addr,
 	  shdr->sh_offset,
 	  (unsigned int) shdr->sh_link,
-	  elf_strptr (ebl->elf, shstrndx,
-		      gelf_getshdr (elf_getscn (ebl->elf, shdr->sh_link),
-				    &glink)->sh_name));
+	  elf_strptr (ebl->elf, shstrndx, glink->sh_name));
 
   if (extrastr != NULL)
     fputs (extrastr, stdout);
@@ -3078,7 +3114,8 @@ print_liblist (Ebl *ebl)
 
       if (shdr != NULL && shdr->sh_type == SHT_GNU_LIBLIST)
 	{
-	  int nentries = shdr->sh_size / shdr->sh_entsize;
+	  size_t sh_entsize = gelf_fsize (ebl->elf, ELF_T_LIB, 1, EV_CURRENT);
+	  int nentries = shdr->sh_size / sh_entsize;
 	  printf (ngettext ("\
 \nLibrary list section [%2zu] '%s' at offset %#0" PRIx64 " contains %d entry:\n",
 			    "\
@@ -4403,6 +4440,16 @@ print_decoded_aranges_section (Ebl *ebl,
       return;
     }
 
+  GElf_Shdr glink_mem;
+  GElf_Shdr *glink;
+  glink = gelf_getshdr (elf_getscn (ebl->elf, shdr->sh_link), &glink_mem);
+  if (glink == NULL)
+    {
+      error (0, 0, gettext ("invalid sh_link value in section %Zu"),
+	     elf_ndxscn (scn));
+      return;
+    }
+
   printf (ngettext ("\
 \nDWARF section [%2zu] '%s' at offset %#" PRIx64 " contains %zu entry:\n",
 		    "\
--- a/src/strip.c
+++ b/src/strip.c
@@ -581,6 +581,11 @@ handle_elf (int fd, Elf *elf, const char
       goto fail_close;
     }
 
+  if (shstrndx >= shnum)
+    goto illformed;
+
+#define elf_assert(test) do { if (!(test)) goto illformed; } while (0)
+
   /* Storage for section information.  We leave room for two more
      entries since we unconditionally create a section header string
      table.  Maybe some weird tool created an ELF file without one.
@@ -602,7 +607,7 @@ handle_elf (int fd, Elf *elf, const char
     {
       /* This should always be true (i.e., there should not be any
 	 holes in the numbering).  */
-      assert (elf_ndxscn (scn) == cnt);
+      elf_assert (elf_ndxscn (scn) == cnt);
 
       shdr_info[cnt].scn = scn;
 
@@ -615,6 +620,7 @@ handle_elf (int fd, Elf *elf, const char
 					shdr_info[cnt].shdr.sh_name);
       if (shdr_info[cnt].name == NULL)
 	{
+	illformed:
 	  error (0, 0, gettext ("illformed file '%s'"), fname);
 	  goto fail_close;
 	}
@@ -624,6 +630,8 @@ handle_elf (int fd, Elf *elf, const char
 
       /* Remember the shdr.sh_link value.  */
       shdr_info[cnt].old_sh_link = shdr_info[cnt].shdr.sh_link;
+      if (shdr_info[cnt].old_sh_link >= shnum)
+	goto illformed;
 
       /* Sections in files other than relocatable object files which
 	 are not loaded can be freely moved by us.  In relocatable
@@ -636,7 +644,7 @@ handle_elf (int fd, Elf *elf, const char
 	 appropriate reference.  */
       if (unlikely (shdr_info[cnt].shdr.sh_type == SHT_SYMTAB_SHNDX))
 	{
-	  assert (shdr_info[shdr_info[cnt].shdr.sh_link].symtab_idx == 0);
+	  elf_assert (shdr_info[shdr_info[cnt].shdr.sh_link].symtab_idx == 0);
 	  shdr_info[shdr_info[cnt].shdr.sh_link].symtab_idx = cnt;
 	}
       else if (unlikely (shdr_info[cnt].shdr.sh_type == SHT_GROUP))
@@ -653,7 +661,12 @@ handle_elf (int fd, Elf *elf, const char
 	  for (inner = 1;
 	       inner < shdr_info[cnt].data->d_size / sizeof (Elf32_Word);
 	       ++inner)
+	    {
+	      if (grpref[inner] < shnum)
 	    shdr_info[grpref[inner]].group_idx = cnt;
+	      else
+		goto illformed;
+	    }
 
 	  if (inner == 1 || (inner == 2 && (grpref[0] & GRP_COMDAT) == 0))
 	    /* If the section group contains only one element and this
@@ -664,7 +677,7 @@ handle_elf (int fd, Elf *elf, const char
 	}
       else if (unlikely (shdr_info[cnt].shdr.sh_type == SHT_GNU_versym))
 	{
-	  assert (shdr_info[shdr_info[cnt].shdr.sh_link].version_idx == 0);
+	  elf_assert (shdr_info[shdr_info[cnt].shdr.sh_link].version_idx == 0);
 	  shdr_info[shdr_info[cnt].shdr.sh_link].version_idx = cnt;
 	}
 
@@ -672,7 +685,7 @@ handle_elf (int fd, Elf *elf, const char
 	 discarded right away.  */
       if ((shdr_info[cnt].shdr.sh_flags & SHF_GROUP) != 0)
 	{
-	  assert (shdr_info[cnt].group_idx != 0);
+	  elf_assert (shdr_info[cnt].group_idx != 0);
 
 	  if (shdr_info[shdr_info[cnt].group_idx].idx == 0)
 	    {
@@ -748,10 +761,14 @@ handle_elf (int fd, Elf *elf, const char
 	    {
 	      /* If a relocation section is marked as being removed make
 		 sure the section it is relocating is removed, too.  */
-	      if ((shdr_info[cnt].shdr.sh_type == SHT_REL
+	      if (shdr_info[cnt].shdr.sh_type == SHT_REL
 		   || shdr_info[cnt].shdr.sh_type == SHT_RELA)
-		  && shdr_info[shdr_info[cnt].shdr.sh_info].idx != 0)
-		shdr_info[cnt].idx = 1;
+		{
+		  if (shdr_info[cnt].shdr.sh_info >= shnum)
+		    goto illformed;
+		  else if (shdr_info[shdr_info[cnt].shdr.sh_info].idx != 0)
+		    shdr_info[cnt].idx = 1;
+		}
 
 	      /* If a group section is marked as being removed make
 		 sure all the sections it contains are being removed, too.  */
@@ -795,7 +812,7 @@ handle_elf (int fd, Elf *elf, const char
 		  if (shdr_info[cnt].symtab_idx != 0
 		      && shdr_info[shdr_info[cnt].symtab_idx].data == NULL)
 		    {
-		      assert (shdr_info[cnt].shdr.sh_type == SHT_SYMTAB);
+		      elf_assert (shdr_info[cnt].shdr.sh_type == SHT_SYMTAB);
 
 		      shdr_info[shdr_info[cnt].symtab_idx].data
 			= elf_getdata (shdr_info[shdr_info[cnt].symtab_idx].scn,
@@ -835,6 +852,9 @@ handle_elf (int fd, Elf *elf, const char
 		      else if (scnidx == SHN_XINDEX)
 			scnidx = xndx;
 
+		      if (scnidx >= shnum)
+			goto illformed;
+
 		      if (shdr_info[scnidx].idx == 0)
 			/* This symbol table has a real symbol in
 			   a discarded section.  So preserve the
@@ -865,12 +885,16 @@ handle_elf (int fd, Elf *elf, const char
 		}
 
 	      /* Handle references through sh_info.  */
-	      if (SH_INFO_LINK_P (&shdr_info[cnt].shdr)
-		  && shdr_info[shdr_info[cnt].shdr.sh_info].idx == 0)
+	      if (SH_INFO_LINK_P (&shdr_info[cnt].shdr))
+		{
+		  if (shdr_info[cnt].shdr.sh_info >= shnum)
+		    goto illformed;
+		  else if ( shdr_info[shdr_info[cnt].shdr.sh_info].idx == 0)
 		{
 		  shdr_info[shdr_info[cnt].shdr.sh_info].idx = 1;
 		  changes |= shdr_info[cnt].shdr.sh_info < cnt;
 		}
+		}
 
 	      /* Mark the section as investigated.  */
 	      shdr_info[cnt].idx = 2;
@@ -1011,7 +1035,7 @@ handle_elf (int fd, Elf *elf, const char
 	  error (EXIT_FAILURE, 0, gettext ("while generating output file: %s"),
 		 elf_errmsg (-1));
 
-	assert (elf_ndxscn (shdr_info[cnt].newscn) == shdr_info[cnt].idx);
+	elf_assert (elf_ndxscn (shdr_info[cnt].newscn) == shdr_info[cnt].idx);
 
 	/* Add this name to the section header string table.  */
 	shdr_info[cnt].se = ebl_strtabadd (shst, shdr_info[cnt].name, 0);
@@ -1048,7 +1072,7 @@ handle_elf (int fd, Elf *elf, const char
 	error (EXIT_FAILURE, 0,
 	       gettext ("while create section header section: %s"),
 	       elf_errmsg (-1));
-      assert (elf_ndxscn (shdr_info[cnt].newscn) == shdr_info[cnt].idx);
+      elf_assert (elf_ndxscn (shdr_info[cnt].newscn) == shdr_info[cnt].idx);
 
       shdr_info[cnt].data = elf_newdata (shdr_info[cnt].newscn);
       if (shdr_info[cnt].data == NULL)
@@ -1105,7 +1129,7 @@ handle_elf (int fd, Elf *elf, const char
     error (EXIT_FAILURE, 0,
 	   gettext ("while create section header section: %s"),
 	   elf_errmsg (-1));
-  assert (elf_ndxscn (shdr_info[cnt].newscn) == idx);
+  elf_assert (elf_ndxscn (shdr_info[cnt].newscn) == idx);
 
   /* Finalize the string table and fill in the correct indices in the
      section headers.  */
@@ -1195,20 +1219,20 @@ handle_elf (int fd, Elf *elf, const char
 		    shndxdata = elf_getdata (shdr_info[shdr_info[cnt].symtab_idx].scn,
 					     NULL);
 
-		    assert ((versiondata->d_size / sizeof (Elf32_Word))
+		    elf_assert ((versiondata->d_size / sizeof (Elf32_Word))
 			    >= shdr_info[cnt].data->d_size / elsize);
 		  }
 
 		if (shdr_info[cnt].version_idx != 0)
 		  {
-		    assert (shdr_info[cnt].shdr.sh_type == SHT_DYNSYM);
+		    elf_assert (shdr_info[cnt].shdr.sh_type == SHT_DYNSYM);
 		    /* This section has associated version
 		       information.  We have to modify that
 		       information, too.  */
 		    versiondata = elf_getdata (shdr_info[shdr_info[cnt].version_idx].scn,
 					       NULL);
 
-		    assert ((versiondata->d_size / sizeof (GElf_Versym))
+		    elf_assert ((versiondata->d_size / sizeof (GElf_Versym))
 			    >= shdr_info[cnt].data->d_size / elsize);
 		  }
 
@@ -1263,7 +1287,7 @@ handle_elf (int fd, Elf *elf, const char
 		      sec = shdr_info[sym->st_shndx].idx;
 		    else
 		      {
-			assert (shndxdata != NULL);
+			elf_assert (shndxdata != NULL);
 
 			sec = shdr_info[xshndx].idx;
 		      }
@@ -1284,7 +1308,7 @@ handle_elf (int fd, Elf *elf, const char
 			    nxshndx = sec;
 			  }
 
-			assert (sec < SHN_LORESERVE || shndxdata != NULL);
+			elf_assert (sec < SHN_LORESERVE || shndxdata != NULL);
 
 			if ((inner != destidx || nshndx != sym->st_shndx
 			     || (shndxdata != NULL && nxshndx != xshndx))
@@ -1311,9 +1335,11 @@ handle_elf (int fd, Elf *elf, const char
 		      {
 			size_t sidx = (sym->st_shndx != SHN_XINDEX
 					? sym->st_shndx : xshndx);
-			assert (GELF_ST_TYPE (sym->st_info) == STT_SECTION
-				|| (shdr_info[sidx].shdr.sh_type == SHT_GROUP
-				    && shdr_info[sidx].shdr.sh_info == inner));
+			elf_assert (GELF_ST_TYPE (sym->st_info) == STT_SECTION
+				    || ((shdr_info[sidx].shdr.sh_type
+					 == SHT_GROUP)
+					&& (shdr_info[sidx].shdr.sh_info
+					    == inner)));
 		      }
 		  }
 
@@ -1501,11 +1527,11 @@ handle_elf (int fd, Elf *elf, const char
 		  {
 		    GElf_Sym sym_mem;
 		    GElf_Sym *sym = gelf_getsym (symd, inner, &sym_mem);
-		    assert (sym != NULL);
+		    elf_assert (sym != NULL);
 
 		    const char *name = elf_strptr (elf, strshndx,
 						   sym->st_name);
-		    assert (name != NULL);
+		    elf_assert (name != NULL);
 		    size_t hidx = elf_hash (name) % nbucket;
 
 		    if (bucket[hidx] == 0)
@@ -1524,8 +1550,8 @@ handle_elf (int fd, Elf *elf, const char
 	    else
 	      {
 		/* Alpha and S390 64-bit use 64-bit SHT_HASH entries.  */
-		assert (shdr_info[cnt].shdr.sh_entsize
-			== sizeof (Elf64_Xword));
+		elf_assert (shdr_info[cnt].shdr.sh_entsize
+                            == sizeof (Elf64_Xword));
 
 		Elf64_Xword *bucket = (Elf64_Xword *) hashd->d_buf;
 
@@ -1555,11 +1581,11 @@ handle_elf (int fd, Elf *elf, const char
 		  {
 		    GElf_Sym sym_mem;
 		    GElf_Sym *sym = gelf_getsym (symd, inner, &sym_mem);
-		    assert (sym != NULL);
+		    elf_assert (sym != NULL);
 
 		    const char *name = elf_strptr (elf, strshndx,
 						   sym->st_name);
-		    assert (name != NULL);
+		    elf_assert (name != NULL);
 		    size_t hidx = elf_hash (name) % nbucket;
 
 		    if (bucket[hidx] == 0)