From: Jesper Juhl <jesper.juhl@gmail.com>
Date: Sun, 25 Jun 2006 12:47:09 +0000 (-0700)
Subject: [PATCH] ensure NULL deref can't possibly happen in is_exported()
X-Git-Tag: v2.6.18-rc1~1038
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f867d2a2e5f3f0ce6356f452cc27b70d577de7c7;p=linux-2.6

[PATCH] ensure NULL deref can't possibly happen in is_exported()

If CONFIG_KALLSYMS is defined and if it should happen that is_exported() is
given a NULL 'mod' and lookup_symbol(name, __start___ksymtab,
__stop___ksymtab) returns 0, then we'll end up dereferencing a NULL
pointer.

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/kernel/module.c b/kernel/module.c
index bbe04862e1..d75275de1c 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1326,7 +1326,7 @@ int is_exported(const char *name, const struct module *mod)
 	if (!mod && lookup_symbol(name, __start___ksymtab, __stop___ksymtab))
 		return 1;
 	else
-		if (lookup_symbol(name, mod->syms, mod->syms + mod->num_syms))
+		if (mod && lookup_symbol(name, mod->syms, mod->syms + mod->num_syms))
 			return 1;
 		else
 			return 0;