svn commit: r326243 - stable/10/sys/kern

[Xin LI]

Author: delphij
Date: Mon Nov 27 03:49:51 2017
New Revision: 326243
URL: https://svnweb.freebsd.org/changeset/base/326243

Log:
  MFC r325755: Be more careful when doing calculation with request from
  userland.

Modified:
  stable/10/sys/kern/kern_proc.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/sys/kern/kern_proc.c
==============================================================================
--- stable/10/sys/kern/kern_proc.c	Mon Nov 27 03:47:12 2017	(r326242)
+++ stable/10/sys/kern/kern_proc.c	Mon Nov 27 03:49:51 2017	(r326243)
@@ -1858,7 +1858,7 @@ sysctl_kern_proc_args(SYSCTL_HANDLER_ARGS)
 	if (error != 0 || req->newptr == NULL)
 		return (error);
 
-	if (req->newlen + sizeof(struct pargs) > ps_arg_cache_limit)
+	if (req->newlen > ps_arg_cache_limit - sizeof(struct pargs))
 		return (ENOMEM);
 	newpa = pargs_alloc(req->newlen);
 	error = SYSCTL_IN(req, newpa->ar_args, req->newlen);