[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>

1 files changed, 1 insertions, 1 deletions

diff --git a/kernel/module.c b/kernel/module.c
index bbe04862e1b0..d75275de1c28 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;