Index: procfs_regs.c
===================================================================
RCS file: /home/cvsup/freebsd/CVS/src/sys/miscfs/procfs/procfs_regs.c,v
retrieving revision 1.3
retrieving revision 1.3.4.1
diff -u -r1.3 -r1.3.4.1
--- procfs_regs.c	1996/01/24 18:41:25	1.3
+++ procfs_regs.c	1997/08/12 04:45:25	1.3.4.1
@@ -62,6 +62,8 @@
 	char *kv;
 	int kl;
 
+	if (!CHECKIO(curp, p))
+		return EPERM;
 	kl = sizeof(r);
 	kv = (char *) &r;
 
Index: procfs.h
===================================================================
RCS file: /home/cvsup/freebsd/CVS/src/sys/miscfs/procfs/procfs.h,v
retrieving revision 1.12
retrieving revision 1.12.2.1
diff -u -r1.12 -r1.12.2.1
--- procfs.h	1996/07/02 13:38:07	1.12
+++ procfs.h	1997/08/12 04:45:20	1.12.2.1
@@ -83,6 +83,18 @@
 	  (bcmp((s), (cnp)->cn_nameptr, (len)) == 0))
 
 #define KMEM_GROUP 2
+
+/*
+ * Check to see whether access to target process is allowed
+ * Evaluates to 1 if access is allowed.
+ */
+#define CHECKIO(p1, p2) \
+     ((((p1)->p_cred->pc_ucred->cr_uid == (p2)->p_cred->p_ruid) && \
+       ((p1)->p_cred->p_ruid == (p2)->p_cred->p_ruid) && \
+       ((p1)->p_cred->p_svuid == (p2)->p_cred->p_ruid) && \
+       ((p2)->p_flag & P_SUGID) == 0) || \
+      (suser((p1)->p_cred->pc_ucred, &(p1)->p_acflag) == 0))
+      
 /*
  * Format of a directory entry in /proc, ...
  * This must map onto struct dirent (see <dirent.h>)
Index: procfs_mem.c
===================================================================
RCS file: /home/cvsup/freebsd/CVS/src/sys/miscfs/procfs/procfs_mem.c,v
retrieving revision 1.20
retrieving revision 1.20.2.1
diff -u -r1.20 -r1.20.2.1
--- procfs_mem.c	1996/10/24 02:47:05	1.20
+++ procfs_mem.c	1997/08/12 04:45:23	1.20.2.1
@@ -300,6 +300,23 @@
 	if (uio->uio_resid == 0)
 		return (0);
 
+ 	/*
+ 	 * XXX
+ 	 * We need to check for KMEM_GROUP because ps is sgid kmem;
+ 	 * not allowing it here causes ps to not work properly.  Arguably,
+ 	 * this is a bug with what ps does.  We only need to do this
+ 	 * for Pmem nodes, and only if it's reading.  This is still not
+ 	 * good, as it may still be possible to grab illicit data if
+ 	 * a process somehow gets to be KMEM_GROUP.  Note that this also
+ 	 * means that KMEM_GROUP can't change without editing procfs.h!
+ 	 * All in all, quite yucky.
+ 	 */
+  
+	if (!CHECKIO(curp, p) &&
+ 	    !(curp->p_cred->pc_ucred->cr_gid == KMEM_GROUP &&
+ 	      uio->uio_rw == UIO_READ))
+  		return EPERM;
+ 
 	error = procfs_rwmem(p, uio);
 
 	return (error);
Index: procfs_vnops.c
===================================================================
RCS file: /home/cvsup/freebsd/CVS/src/sys/miscfs/procfs/procfs_vnops.c,v
retrieving revision 1.24
retrieving revision 1.24.2.1
diff -u -r1.24 -r1.24.2.1
--- procfs_vnops.c	1996/09/03 14:23:10	1.24
+++ procfs_vnops.c	1997/08/12 04:45:27	1.24.2.1
@@ -120,16 +120,21 @@
 	struct vop_open_args *ap;
 {
 	struct pfsnode *pfs = VTOPFS(ap->a_vp);
+	struct proc *p1 = ap->a_p, *p2 = PFIND(pfs->pfs_pid);
+
+	if (p2 == NULL)
+		return ENOENT;
 
 	switch (pfs->pfs_type) {
 	case Pmem:
-		if (PFIND(pfs->pfs_pid) == 0)
-			return (ENOENT);	/* was ESRCH, jsp */
-
 		if (((pfs->pfs_flags & FWRITE) && (ap->a_mode & O_EXCL)) ||
 			((pfs->pfs_flags & O_EXCL) && (ap->a_mode & FWRITE)))
 			return (EBUSY);
 
+		if (!CHECKIO(p1, p2) &&
+		    (p1->p_cred->pc_ucred->cr_gid != KMEM_GROUP))
+			return EPERM;
+
 
 		if (ap->a_mode & FWRITE)
 			pfs->pfs_flags = ap->a_mode & (FWRITE|O_EXCL);
@@ -176,7 +181,6 @@
 procfs_ioctl(ap)
 	struct vop_ioctl_args *ap;
 {
-
 	return (ENOTTY);
 }
 
Index: procfs_fpregs.c
===================================================================
RCS file: /home/cvsup/freebsd/CVS/src/sys/miscfs/procfs/procfs_fpregs.c,v
retrieving revision 1.3
retrieving revision 1.3.4.1
diff -u -r1.3 -r1.3.4.1
--- procfs_fpregs.c	1996/01/24 18:40:56	1.3
+++ procfs_fpregs.c	1997/08/12 05:24:20	1.3.4.1
@@ -62,6 +62,8 @@
 	char *kv;
 	int kl;
 
+	if (!CHECKIO(curp, p))
+		return EPERM;
 	kl = sizeof(r);
 	kv = (char *) &r;