Fix assertion failure in the BFD library when called to parse a file containing corrupt ELF group information.

PR 25699
	* elf.c (bfd_elf_set_group_contents): Replace assertion with an
	error return.

bfd/ChangeLog

@@ -1,3 +1,9 @@
+2020-03-19  Nick Clifton  <nickc@redhat.com>
+
+	PR 25699
+	* elf.c (bfd_elf_set_group_contents): Replace assertion with an
+	error return.
+
 2020-03-19  Sebastian Huber  <sebastian.huber@embedded-brains.de>
 
 	* elfxx-riscv.c (riscv_parse_subset): Don't use C99.

bfd/elf.c

@@ -3533,8 +3533,13 @@ bfd_elf_set_group_contents (bfd *abfd, asection *sec, void *failedptrarg)
       if (symindx == 0)
 	{
 	  /* If called from the assembler, swap_out_syms will have set up
-	     elf_section_syms.  */
-	  BFD_ASSERT (elf_section_syms (abfd) != NULL);
+	     elf_section_syms.
+	     PR 25699: A corrupt input file could contain bogus group info.  */
+	  if (elf_section_syms (abfd) == NULL)
+	    {
+	      *failedptr = TRUE;
+	      return;
+	    }
 	  symindx = elf_section_syms (abfd)[sec->index]->udata.i;
 	}
       elf_section_data (sec)->this_hdr.sh_info = symindx;