[src/trunk]: src/sys/kern prevent cross-mount operations.

[yamt <yamt%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/343d05123f2f
branches:  trunk
changeset: 763168:343d05123f2f
user:      yamt <yamt%NetBSD.org@localhost>
date:      Sat Mar 12 07:16:50 2011 +0000

description:
prevent cross-mount operations.

diffstat:

 sys/kern/vfs_syscalls.c |  37 +++++++++++++++++++++++++++----------
 1 files changed, 27 insertions(+), 10 deletions(-)

diffs (73 lines):

diff -r d919034268df -r 343d05123f2f sys/kern/vfs_syscalls.c
--- a/sys/kern/vfs_syscalls.c   Sat Mar 12 05:23:41 2011 +0000
+++ b/sys/kern/vfs_syscalls.c   Sat Mar 12 07:16:50 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: vfs_syscalls.c,v 1.418 2011/03/06 17:08:36 bouyer Exp $        */
+/*     $NetBSD: vfs_syscalls.c,v 1.419 2011/03/12 07:16:50 yamt Exp $  */
 
 /*-
  * Copyright (c) 2008, 2009 The NetBSD Foundation, Inc.
@@ -66,7 +66,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_syscalls.c,v 1.418 2011/03/06 17:08:36 bouyer Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_syscalls.c,v 1.419 2011/03/12 07:16:50 yamt Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_fileassoc.h"
@@ -2085,14 +2085,15 @@
        if ((error = namei(&nd)) != 0)
                goto out2;
        if (nd.ni_vp) {
-               VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd);
-               if (nd.ni_dvp == nd.ni_vp)
-                       vrele(nd.ni_dvp);
-               else
-                       vput(nd.ni_dvp);
-               vrele(nd.ni_vp);
                error = EEXIST;
-               goto out2;
+               goto abortop;
+       }
+       /*
+        * Prevent cross-mount operation.
+        */
+       if (nd.ni_dvp->v_mount != vp->v_mount) {
+               error = EXDEV;
+               goto abortop;
        }
        error = VOP_LINK(nd.ni_dvp, vp, &nd.ni_cnd);
 out2:
@@ -2100,6 +2101,15 @@
 out1:
        vrele(vp);
        return (error);
+abortop:
+       VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd);
+       if (nd.ni_dvp == nd.ni_vp)
+               vrele(nd.ni_dvp);
+       else
+               vput(nd.ni_dvp);
+       if (nd.ni_vp != NULL)
+               vrele(nd.ni_vp);
+       goto out2;
 }
 
 int
@@ -3568,7 +3578,14 @@
                          fromnd.ni_cnd.cn_namelen))
                error = -1;
        }
-
+       /*
+        * Prevent cross-mount operation.
+        */
+       if (error == 0) {
+               if (tond.ni_dvp->v_mount != fromnd.ni_dvp->v_mount) {
+                       error = EXDEV;
+               }
+       }
 #if NVERIEXEC > 0
        if (!error) {
                char *f1, *f2;