Always call gelf_fsize with EV_CURRENT as argument.

Don't trust the elf version given by the file. It could be completely
bogus. In which case gelf_fsize just returns zero. Which could cause
divide by zero errors.

https://bugzilla.redhat.com/show_bug.cgi?id=1170810#c34

Signed-off-by: Mark Wielaard <mjw@redhat.com>

diff --git a/libelf/ChangeLog b/libelf/ChangeLog
index e9c2a8d..312d5cf 100644 (file)
--- a/libelf/ChangeLog
+++ b/libelf/ChangeLog
@@ -1,3 +1,7 @@
+2015-05-08  Mark Wielaard  <mjw@redhat.com>
+
+       * nlist.c (nlist): Call gelf_fsize with EV_CURRENT.
+
 2015-01-03  Mark Wielaard  <mjw@redhat.com>
 
        * version_xlate.h (elf_cvt_Verdef): Use memmove to copy src to dest.

diff --git a/libelf/nlist.c b/libelf/nlist.c
index 41e5ff6..89fd081 100644 (file)
--- a/libelf/nlist.c
+++ b/libelf/nlist.c
@@ -126,7 +126,7 @@ nlist (const char *filename, struct nlist *nl)
 
   /* How many symbols are there?  */
   nsyms = (shdr->sh_size
-          / INTUSE(gelf_fsize) (elf, ELF_T_SYM, 1, data->d_version));
+          / INTUSE(gelf_fsize) (elf, ELF_T_SYM, 1, EV_CURRENT));
 
   /* Create the hash table.  */
   table = nlist_fshash_init (nsyms);

diff --git a/src/ChangeLog b/src/ChangeLog
index e79f457..55bd4cc 100644 (file)
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2015-05-08  Mark Wielaard  <mjw@redhat.com>
+
+       * nm.c (show_symbols): Call gelf_fsize with EV_CURRENT.
+       * strip.c (handle_elf): Likewise.
+
 2015-05-06  Mark Wielaard  <mjw@redhat.com>
 
        * elflint.c (check_gnu_hash): Return early when 2nd hash function

diff --git a/src/nm.c b/src/nm.c
index 7d20bbb..8d19715 100644 (file)
--- a/src/nm.c
+++ b/src/nm.c
@@ -1166,7 +1166,7 @@ show_symbols (Ebl *ebl, GElf_Ehdr *ehdr, Elf_Scn *scn, Elf_Scn *xndxscn,
 
   /* Consistency checks.  */
   if (entsize == 0
-      || entsize != gelf_fsize (ebl->elf, ELF_T_SYM, 1, ehdr->e_version))
+      || entsize != gelf_fsize (ebl->elf, ELF_T_SYM, 1, EV_CURRENT))
     error (0, 0,
           gettext ("%s: entry size in section %zd `%s' is not what we expect"),
           fullname, elf_ndxscn (scn),

diff --git a/src/strip.c b/src/strip.c
index fd3920d..365b18d 100644 (file)
--- a/src/strip.c
+++ b/src/strip.c
@@ -810,8 +810,7 @@ handle_elf (int fd, Elf *elf, const char *prefix, const char *fname,
 
                  /* Go through all symbols and make sure the section they
                     reference is not removed.  */
-                 size_t elsize = gelf_fsize (elf, ELF_T_SYM, 1,
-                                             ehdr->e_version);
+                 size_t elsize = gelf_fsize (elf, ELF_T_SYM, 1, EV_CURRENT);
 
                  for (size_t inner = 0;
                       inner < shdr_info[cnt].data->d_size / elsize;
@@ -1193,8 +1192,7 @@ handle_elf (int fd, Elf *elf, const char *prefix, const char *fname,
                Elf_Data *versiondata = NULL;
                Elf_Data *shndxdata = NULL;
 
-               size_t elsize = gelf_fsize (elf, ELF_T_SYM, 1,
-                                           ehdr->e_version);
+               size_t elsize = gelf_fsize (elf, ELF_T_SYM, 1, EV_CURRENT);
 
                if (shdr_info[cnt].symtab_idx != 0)
                  {
@@ -1487,8 +1485,7 @@ handle_elf (int fd, Elf *elf, const char *prefix, const char *fname,
                Elf32_Word *bucket = (Elf32_Word *) hashd->d_buf;
 
                size_t strshndx = shdr_info[symtabidx].old_sh_link;
-               size_t elsize = gelf_fsize (elf, ELF_T_SYM, 1,
-                                           ehdr->e_version);
+               size_t elsize = gelf_fsize (elf, ELF_T_SYM, 1, EV_CURRENT);
 
                /* Adjust the nchain value.  The symbol table size
                   changed.  We keep the same size for the bucket array.  */
@@ -1541,8 +1538,7 @@ handle_elf (int fd, Elf *elf, const char *prefix, const char *fname,
                Elf64_Xword *bucket = (Elf64_Xword *) hashd->d_buf;
 
                size_t strshndx = shdr_info[symtabidx].old_sh_link;
-               size_t elsize = gelf_fsize (elf, ELF_T_SYM, 1,
-                                           ehdr->e_version);
+               size_t elsize = gelf_fsize (elf, ELF_T_SYM, 1, EV_CURRENT);
 
                /* Adjust the nchain value.  The symbol table size
                   changed.  We keep the same size for the bucket array.  */
@@ -1611,8 +1607,7 @@ handle_elf (int fd, Elf *elf, const char *prefix, const char *fname,
            GElf_Half *verstab = (GElf_Half *) verd->d_buf;
 
            /* Walk through the list and */
-           size_t elsize = gelf_fsize (elf, verd->d_type, 1,
-                                       ehdr->e_version);
+           size_t elsize = gelf_fsize (elf, verd->d_type, 1, EV_CURRENT);
            for (size_t inner = 1; inner < verd->d_size / elsize; ++inner)
              if (newsymidx[inner] != 0)
                /* Overwriting the same array works since the
@@ -1624,8 +1619,8 @@ handle_elf (int fd, Elf *elf, const char *prefix, const char *fname,
            verd->d_size = gelf_fsize (newelf, verd->d_type,
                                       symd->d_size
                                       / gelf_fsize (elf, symd->d_type, 1,
-                                                    ehdr->e_version),
-                                      ehdr->e_version);
+                                                    EV_CURRENT),
+                                      EV_CURRENT);
            update_section_size (verd);
            break;