From: tobhe <tobhe@openbsd.org>
Date: Fri, 21 Jan 2022 14:07:06 +0000 (+0000)
Subject: Fix NULL dereference which allows user programs to read parts
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=2b183ca97f861a11598ca833fea167bf6089417a;p=openbsd

Fix NULL dereference which allows user programs to read parts
of the kernel memory.  Found with clang static analyzer.

Feedback and ok gkoehler@
ok bluhm@
---

diff --git a/sys/arch/powerpc/powerpc/trap.c b/sys/arch/powerpc/powerpc/trap.c
index 6e12ceb4ee4..990615fbae4 100644
--- a/sys/arch/powerpc/powerpc/trap.c
+++ b/sys/arch/powerpc/powerpc/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.124 2022/01/20 14:02:51 tobhe Exp $	*/
+/*	$OpenBSD: trap.c,v 1.125 2022/01/21 14:07:06 tobhe Exp $	*/
 /*	$NetBSD: trap.c,v 1.3 1996/10/13 03:31:37 christos Exp $	*/
 
 /*
@@ -154,7 +154,7 @@ void
 enable_vec(struct proc *p)
 {
 	struct pcb *pcb = &p->p_addr->u_pcb;
-	struct vreg *pcb_vr = pcb->pcb_vr;
+	struct vreg *pcb_vr;
 	struct cpu_info *ci = curcpu();
 	u_int32_t oldmsr, msr;
 
@@ -163,6 +163,7 @@ enable_vec(struct proc *p)
 	 */
 	if (pcb->pcb_vr == NULL)
 		pcb->pcb_vr = pool_get(&ppc_vecpl, PR_WAITOK | PR_ZERO);
+	pcb_vr = pcb->pcb_vr;
 
 	if (curcpu()->ci_vecproc != NULL || pcb->pcb_veccpu != NULL)
 		printf("attempting to restore vector in use vecproc %p"