strings: Handle failure of getting section name on bogus section data.

If there is something wrong with getting the section data it is likely
we won't be able to get the actual section name because the file is
somehow corrupted. Try to get the name, but handle failure gracefully.

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

diff --git a/src/ChangeLog b/src/ChangeLog
index 15e6fae..3d7761f 100644 (file)
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2015-06-18  Mark Wielaard  <mjw@redhat.com>
+
+       * strings.c (readelf): Use "<unknown>" if we cannot retrieve section
+       name.
+
 2015-06-09  Mark Wielaard  <mjw@redhat.com>
 
        * addr2line.c (print_dwarf_function): Always free scopes before

diff --git a/src/strings.c b/src/strings.c
index b2bce7b..88a3c2f 100644 (file)
--- a/src/strings.c
+++ b/src/strings.c
@@ -730,10 +730,14 @@ read_elf (Elf *elf, int fd, const char *fname, off64_t fdlen)
              || fdlen - shdr->sh_offset < shdr->sh_size)
            {
              size_t strndx = 0;
-             elf_getshdrstrndx (elf, &strndx);
+             const char *sname;
+             if (unlikely (elf_getshdrstrndx (elf, &strndx) < 0))
+               sname = "<unknown>";
+             else
+               sname = elf_strptr (elf, strndx, shdr->sh_name) ?: "<unknown>";
              error (0, 0,
                     gettext ("Skipping section %zd '%s' data outside file"),
-                    elf_ndxscn (scn), elf_strptr (elf, strndx, shdr->sh_name));
+                    elf_ndxscn (scn), sname);
              result = 1;
            }
          else