[PATCH] Don't OOPS on stripped modules

Don't want to go overboard with the checks, but this is simple and
reasonable.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (modified)
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade_spam@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

kernel/module.c

@@ -1538,9 +1538,6 @@ static struct module *load_module(void __user *umod,
 	secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
 	sechdrs[0].sh_addr = 0;
 
-	/* And these should exist, but gcc whinges if we don't init them */
-	symindex = strindex = 0;
-
 	for (i = 1; i < hdr->e_shnum; i++) {
 		if (sechdrs[i].sh_type != SHT_NOBITS
 		    && len < sechdrs[i].sh_offset + sechdrs[i].sh_size)
@@ -1572,6 +1569,13 @@ static struct module *load_module(void __user *umod,
 	}
 	mod = (void *)sechdrs[modindex].sh_addr;
 
+	if (symindex == 0) {
+		printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
+		       mod->name);
+		err = -ENOEXEC;
+		goto free_hdr;
+	}
+
 	/* Optional sections */
 	exportindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab");
 	gplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl");