asan: readelf leak in hppa_process_unwind

This extracts code reading symbol tables into a common function that
tidies up after errors.  I've also changed an error reporting multiple
string tables to an error on multiple symbol tables.

	* readelf.c (get_symbols): New function.
	(process_relocs, ia64_process_unwind, hppa_process_unwind),
	(arm_process_unwind, get_symbol_for_build_attribute): Use it.

diff --git a/binutils/ChangeLog b/binutils/ChangeLog
index ee1534f98a649178ae44341ede99f2761a04c6d5..dad2ed6c2de5b3666324a0f9a9b7f30242d4042d 100644 (file)
--- a/binutils/ChangeLog
+++ b/binutils/ChangeLog
@@ -1,3 +1,9 @@
+2020-03-16  Alan Modra  <amodra@gmail.com>
+
+       * readelf.c (get_symbols): New function.
+       (process_relocs, ia64_process_unwind, hppa_process_unwind),
+       (arm_process_unwind, get_symbol_for_build_attribute): Use it.
+
 2020-03-16  Alan Modra  <amodra@gmail.com>
 
        * unwind-ia64.c (unw_decode_uleb128): Prevent overlarge shifts.

diff --git a/binutils/readelf.c b/binutils/readelf.c
index 49eb20f28c34f0ef971fc12b3b1e4643b36cd147..a11297845e88a46e3bed0888b4db0fbd629caccf 100644 (file)
--- a/binutils/readelf.c
+++ b/binutils/readelf.c
@@ -6765,6 +6765,47 @@ process_section_headers (Filedata * filedata)
   return TRUE;
 }
 
+static bfd_boolean
+get_symtab (Filedata *filedata, Elf_Internal_Shdr *symsec,
+           Elf_Internal_Sym **symtab, unsigned long *nsyms,
+           char **strtab, unsigned long *strtablen)
+{
+  *strtab = NULL;
+  *strtablen = 0;
+  *symtab = GET_ELF_SYMBOLS (filedata, symsec, nsyms);
+
+  if (*symtab == NULL)
+    return FALSE;
+
+  if (symsec->sh_link != 0)
+    {
+      Elf_Internal_Shdr *strsec;
+
+      if (symsec->sh_link >= filedata->file_header.e_shnum)
+       {
+         error (_("Bad sh_link in symbol table section\n"));
+         free (*symtab);
+         *symtab = NULL;
+         *nsyms = 0;
+         return FALSE;
+       }
+
+      strsec = filedata->section_headers + symsec->sh_link;
+
+      *strtab = (char *) get_data (NULL, filedata, strsec->sh_offset,
+                                  1, strsec->sh_size, _("string table"));
+      if (*strtab == NULL)
+       {
+         free (*symtab);
+         *symtab = NULL;
+         *nsyms = 0;
+         return FALSE;
+       }
+      *strtablen = strsec->sh_size;
+    }
+  return TRUE;
+}
+
 static const char *
 get_group_flags (unsigned int flags)
 {
@@ -7355,7 +7396,6 @@ process_relocs (Filedata * filedata)
 
          if (rel_size)
            {
-             Elf_Internal_Shdr * strsec;
              int is_rela;
              unsigned long num_rela;
 
@@ -7388,22 +7428,10 @@ process_relocs (Filedata * filedata)
                      && symsec->sh_type != SHT_DYNSYM)
                     continue;
 
-                 symtab = GET_ELF_SYMBOLS (filedata, symsec, & nsyms);
-
-                 if (symtab == NULL)
+                 if (!get_symtab (filedata, symsec,
+                                  &symtab, &nsyms, &strtab, &strtablen))
                    continue;
 
-                 if (symsec->sh_link != 0
-                     && symsec->sh_link < filedata->file_header.e_shnum)
-                   {
-                     strsec = filedata->section_headers + symsec->sh_link;
-
-                     strtab = (char *) get_data (NULL, filedata, strsec->sh_offset,
-                                                 1, strsec->sh_size,
-                                                 _("string table"));
-                     strtablen = strtab == NULL ? 0 : strsec->sh_size;
-                   }
-
                  dump_relocations (filedata, rel_offset, rel_size,
                                    symtab, nsyms, strtab, strtablen,
                                    is_rela,
@@ -7804,7 +7832,6 @@ ia64_process_unwind (Filedata * filedata)
 {
   Elf_Internal_Shdr * sec;
   Elf_Internal_Shdr * unwsec = NULL;
-  Elf_Internal_Shdr * strsec;
   unsigned long i, unwcount = 0, unwstart = 0;
   struct ia64_unw_aux_info aux;
   bfd_boolean res = TRUE;
@@ -7813,22 +7840,19 @@ ia64_process_unwind (Filedata * filedata)
 
   for (i = 0, sec = filedata->section_headers; i < filedata->file_header.e_shnum; ++i, ++sec)
     {
-      if (sec->sh_type == SHT_SYMTAB
-         && sec->sh_link < filedata->file_header.e_shnum)
+      if (sec->sh_type == SHT_SYMTAB)
        {
-         aux.symtab = GET_ELF_SYMBOLS (filedata, sec, & aux.nsyms);
-
-         strsec = filedata->section_headers + sec->sh_link;
-         if (aux.strtab != NULL)
+         if (aux.symtab)
            {
-             error (_("Multiple auxillary string tables encountered\n"));
+             error (_("Multiple symbol tables encountered\n"));
+             free (aux.symtab);
+             aux.symtab = NULL;
              free (aux.strtab);
-             res = FALSE;
+             aux.strtab = NULL;
            }
-         aux.strtab = (char *) get_data (NULL, filedata, strsec->sh_offset,
-                                          1, strsec->sh_size,
-                                          _("string table"));
-         aux.strtab_size = aux.strtab != NULL ? strsec->sh_size : 0;
+         if (!get_symtab (filedata, sec, &aux.symtab, &aux.nsyms,
+                          &aux.strtab, &aux.strtab_size))
+           return FALSE;
        }
       else if (sec->sh_type == SHT_IA_64_UNWIND)
        unwcount++;
@@ -8265,7 +8289,6 @@ hppa_process_unwind (Filedata * filedata)
 {
   struct hppa_unw_aux_info aux;
   Elf_Internal_Shdr * unwsec = NULL;
-  Elf_Internal_Shdr * strsec;
   Elf_Internal_Shdr * sec;
   unsigned long i;
   bfd_boolean res = TRUE;
@@ -8277,22 +8300,19 @@ hppa_process_unwind (Filedata * filedata)
 
   for (i = 0, sec = filedata->section_headers; i < filedata->file_header.e_shnum; ++i, ++sec)
     {
-      if (sec->sh_type == SHT_SYMTAB
-         && sec->sh_link < filedata->file_header.e_shnum)
+      if (sec->sh_type == SHT_SYMTAB)
        {
-         aux.symtab = GET_ELF_SYMBOLS (filedata, sec, & aux.nsyms);
-
-         strsec = filedata->section_headers + sec->sh_link;
-         if (aux.strtab != NULL)
+         if (aux.symtab)
            {
-             error (_("Multiple auxillary string tables encountered\n"));
+             error (_("Multiple symbol tables encountered\n"));
+             free (aux.symtab);
+             aux.symtab = NULL;
              free (aux.strtab);
-             res = FALSE;
+             aux.strtab = NULL;
            }
-         aux.strtab = (char *) get_data (NULL, filedata, strsec->sh_offset,
-                                          1, strsec->sh_size,
-                                          _("string table"));
-         aux.strtab_size = aux.strtab != NULL ? strsec->sh_size : 0;
+         if (!get_symtab (filedata, sec, &aux.symtab, &aux.nsyms,
+                          &aux.strtab, &aux.strtab_size))
+           return FALSE;
        }
       else if (streq (SECTION_NAME (sec), ".PARISC.unwind"))
        unwsec = sec;
@@ -9363,7 +9383,6 @@ arm_process_unwind (Filedata * filedata)
 {
   struct arm_unw_aux_info aux;
   Elf_Internal_Shdr *unwsec = NULL;
-  Elf_Internal_Shdr *strsec;
   Elf_Internal_Shdr *sec;
   unsigned long i;
   unsigned int sec_type;
@@ -9393,22 +9412,19 @@ arm_process_unwind (Filedata * filedata)
 
   for (i = 0, sec = filedata->section_headers; i < filedata->file_header.e_shnum; ++i, ++sec)
     {
-      if (sec->sh_type == SHT_SYMTAB && sec->sh_link < filedata->file_header.e_shnum)
+      if (sec->sh_type == SHT_SYMTAB)
        {
-         aux.symtab = GET_ELF_SYMBOLS (filedata, sec, & aux.nsyms);
-
-         strsec = filedata->section_headers + sec->sh_link;
-
-         /* PR binutils/17531 file: 011-12666-0.004.  */
-         if (aux.strtab != NULL)
+         if (aux.symtab)
            {
-             error (_("Multiple string tables found in file.\n"));
+             error (_("Multiple symbol tables encountered\n"));
+             free (aux.symtab);
+             aux.symtab = NULL;
              free (aux.strtab);
-             res = FALSE;
+             aux.strtab = NULL;
            }
-         aux.strtab = get_data (NULL, filedata, strsec->sh_offset,
-                                1, strsec->sh_size, _("string table"));
-         aux.strtab_size = aux.strtab != NULL ? strsec->sh_size : 0;
+         if (!get_symtab (filedata, sec, &aux.symtab, &aux.nsyms,
+                          &aux.strtab, &aux.strtab_size))
+           return FALSE;
        }
       else if (sec->sh_type == sec_type)
        unwsec = sec;
@@ -18836,31 +18852,11 @@ get_symbol_for_build_attribute (Filedata *       filedata,
           symsec < filedata->section_headers + filedata->file_header.e_shnum;
           symsec ++)
        {
-         if (symsec->sh_type == SHT_SYMTAB)
-           {
-             ba_cache.symtab = GET_ELF_SYMBOLS (filedata, symsec,
-                                                &ba_cache.nsyms);
-
-             if (ba_cache.symtab != NULL
-                 && symsec->sh_link < filedata->file_header.e_shnum)
-               {
-                 Elf_Internal_Shdr *strtab_sec
-                   = filedata->section_headers + symsec->sh_link;
-
-                 ba_cache.strtab
-                   = (char *) get_data (NULL, filedata, strtab_sec->sh_offset,
-                                        1, strtab_sec->sh_size,
-                                        _("string table"));
-                 ba_cache.strtablen = strtab_sec->sh_size;
-               }
-             if (ba_cache.strtab == NULL)
-               {
-                 free (ba_cache.symtab);
-                 ba_cache.symtab = NULL;
-               }
-             if (ba_cache.symtab != NULL)
-               break;
-           }
+         if (symsec->sh_type == SHT_SYMTAB
+             && get_symtab (filedata, symsec,
+                            &ba_cache.symtab, &ba_cache.nsyms,
+                            &ba_cache.strtab, &ba_cache.strtablen))
+           break;
        }
       ba_cache.filedata = filedata;
     }