[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>

1 files changed, 3 insertions, 16 deletions

diff --git a/kernel/module.c b/kernel/module.c
index fb404299082e..54623c714bba 100644
--- 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;