[PATCH] Fix strlen_user usage in module.c

From: Rusty Russell (rusty@rustcorp.com.au)
Date: Sun Jan 12 2003 - 22:42:57 EST

Spotted by Andi Kleen. strlen_user *is* documented, I just made
assumptions.

Name: Fix strlen_user usage
Author: Rusty Russell
Status: Trivial

D: strlen_user returns 0 on error, not an error number, and otherwise
D: returns the length including the NUL byte. Found by Andi Kleen.

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .22129-linux-2.5.55/kernel/module.c .22129-linux-2.5.55.updated/kernel/module.c
--- .22129-linux-2.5.55/kernel/module.c 2003-01-10 10:55:43.000000000 +1100
+++ .22129-linux-2.5.55.updated/kernel/module.c 2003-01-10 20:55:55.000000000 +1100
@@ -1096,17 +1096,17 @@ static struct module *load_module(void *
         mod = (void *)sechdrs[modindex].sh_addr;
 
         /* Now copy in args */
- err = strlen_user(uargs);
- if (err < 0)
+ arglen = strlen_user(uargs);
+ if (!arglen) {
+ err = -EFAULT;
                 goto free_hdr;
- arglen = err;
-
- args = kmalloc(arglen+1, GFP_KERNEL);
+ }
+ args = kmalloc(arglen, GFP_KERNEL);
         if (!args) {
                 err = -ENOMEM;
                 goto free_hdr;
         }
- if (copy_from_user(args, uargs, arglen+1) != 0) {
+ if (copy_from_user(args, uargs, arglen) != 0) {
                 err = -EFAULT;
                 goto free_mod;
         } 

--
  Anyone who quotes me in their sig is an idiot. -- Rusty Russell.
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