Prevent NULL-pointer call for filesystems that don't provide vfs_sysctl

in their vfsops.

Issue reported by Tim Newsham.

ok claudio@, natano@

diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c
index 7411a92..661b5de 100644 (file)
--- a/sys/kern/vfs_subr.c
+++ b/sys/kern/vfs_subr.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: vfs_subr.c,v 1.248 2016/06/19 11:54:33 natano Exp $   */
+/*     $OpenBSD: vfs_subr.c,v 1.249 2016/07/22 09:54:09 kettenis Exp $ */
 /*     $NetBSD: vfs_subr.c,v 1.53 1996/04/22 01:39:13 christos Exp $   */
 
 /*
@@ -1290,7 +1290,7 @@ vfs_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp,
                        if (vfsp->vfc_typenum == name[0])
                                break;
 
-               if (vfsp == NULL)
+               if (vfsp == NULL || vfsp->vfc_vfsops->vfs_sysctl == NULL)
                        return (EOPNOTSUPP);
 
                return ((*vfsp->vfc_vfsops->vfs_sysctl)(&name[1], namelen - 1,