[PATCH] strndup_user: convert module

Change hand-coded userspace string copying to strndup_user.

Signed-off-by: Davi Arnaut <davi.arnaut@gmail.com>
Cc: David Howells <dhowells@redhat.com>
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 fb404299082ecfa3a6c344c8fe44fb046e58cc6e..54623c714bba38e0f2729a7241445ae8ce46e0d5 100644 (file)
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1572,7 +1572,6 @@ static struct module *load_module(void __user *umod,
                exportindex, modindex, obsparmindex, infoindex, gplindex,
                crcindex, gplcrcindex, versindex, pcpuindex, gplfutureindex,
                gplfuturecrcindex;
-       long arglen;
        struct module *mod;
        long err = 0;
        void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
@@ -1691,23 +1690,11 @@ static struct module *load_module(void __user *umod,
        }
 
        /* Now copy in args */
-       arglen = strlen_user(uargs);
-       if (!arglen) {
-               err = -EFAULT;
-               goto free_hdr;
-       }
-       args = kmalloc(arglen, GFP_KERNEL);
-       if (!args) {
-               err = -ENOMEM;
+       args = strndup_user(uargs, ~0UL >> 1);
+       if (IS_ERR(args)) {
+               err = PTR_ERR(args);
                goto free_hdr;
        }
-       if (copy_from_user(args, uargs, arglen) != 0) {
-               err = -EFAULT;
-               goto free_mod;
-       }
-
-       /* Userspace could have altered the string after the strlen_user() */
-       args[arglen - 1] = '\0';
 
        if (find_module(mod->name)) {
                err = -EEXIST;