From: deraadt <deraadt@openbsd.org>
Date: Thu, 14 Jul 2016 15:39:40 +0000 (+0000)
Subject: kern.usermount=1 is unsafe for everyone, since it allows any non-pledged
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=ae3255761c2f0fd5f127d9467fdc50fa571ae1c9;p=openbsd

kern.usermount=1 is unsafe for everyone, since it allows any non-pledged
program to call the mount/umount system calls.  There is no way any user
can be expected to keep their system safe / reliable with this feature.
Ignore setting to =1, and after release we'll delete the sysctl entirely.
ok lots of people
---

diff --git a/sys/kern/kern_sysctl.c b/sys/kern/kern_sysctl.c
index 24c783637e2..d78d6d76de6 100644
--- a/sys/kern/kern_sysctl.c
+++ b/sys/kern/kern_sysctl.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_sysctl.c,v 1.305 2016/05/27 19:45:04 deraadt Exp $	*/
+/*	$OpenBSD: kern_sysctl.c,v 1.306 2016/07/14 15:39:40 deraadt Exp $	*/
 /*	$NetBSD: kern_sysctl.c,v 1.17 1996/05/20 17:49:05 mrg Exp $	*/
 
 /*-
@@ -275,7 +275,7 @@ kern_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp,
 	int error, level, inthostid, stackgap;
 	dev_t dev;
 	extern int somaxconn, sominconn;
-	extern int usermount, nosuidcoredump;
+	extern int nosuidcoredump;
 	extern int maxlocksperuid;
 	extern int pool_debug;
 	extern int uvm_wxabort;
@@ -414,8 +414,10 @@ kern_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp,
 		return (sysctl_int(oldp, oldlenp, newp, newlen, &somaxconn));
 	case KERN_SOMINCONN:
 		return (sysctl_int(oldp, oldlenp, newp, newlen, &sominconn));
-	case KERN_USERMOUNT:
-		return (sysctl_int(oldp, oldlenp, newp, newlen, &usermount));
+	case KERN_USERMOUNT: {
+		int usermount = 0;
+		return (sysctl_rdint(oldp, oldlenp, newp, usermount));
+		}
 	case KERN_ARND: {
 		char buf[512];
 
diff --git a/sys/kern/vfs_syscalls.c b/sys/kern/vfs_syscalls.c
index 0bb23b084a0..14d22ad9395 100644
--- a/sys/kern/vfs_syscalls.c
+++ b/sys/kern/vfs_syscalls.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vfs_syscalls.c,v 1.262 2016/07/12 20:53:04 millert Exp $	*/
+/*	$OpenBSD: vfs_syscalls.c,v 1.263 2016/07/14 15:39:40 deraadt Exp $	*/
 /*	$NetBSD: vfs_syscalls.c,v 1.71 1996/04/23 10:29:02 mycroft Exp $	*/
 
 /*
@@ -63,7 +63,6 @@
 #include <sys/syscallargs.h>
 
 extern int suid_clear;
-int	usermount = 0;		/* sysctl: by default, users may not mount */
 
 static int change_dir(struct nameidata *, struct proc *);
 
@@ -116,7 +115,7 @@ sys_mount(struct proc *p, void *v, register_t *retval)
 	struct vfsconf *vfsp;
 	int flags = SCARG(uap, flags);
 
-	if (usermount == 0 && (error = suser(p, 0)))
+	if ((error = suser(p, 0)))
 		return (error);
 
 	/*