[src/trunk]: src/sys/uvm fix KASAN PoolUseAfterFree for async write - can't r...

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

details:   https://anonhg.NetBSD.org/src/rev/9f4b6dbb0eba
branches:  trunk
changeset: 933307:9f4b6dbb0eba
user:      jdolecek <jdolecek%NetBSD.org@localhost>
date:      Sun May 24 14:11:49 2020 +0000

description:
fix KASAN PoolUseAfterFree for async write - can't read bp after VOP_STRATEGY()

problem found and fix provided by Paul Ripke

diffstat:

 sys/uvm/uvm_swap.c |  6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diffs (27 lines):

diff -r 262cb893bf63 -r 9f4b6dbb0eba sys/uvm/uvm_swap.c
--- a/sys/uvm/uvm_swap.c        Sun May 24 10:42:27 2020 +0000
+++ b/sys/uvm/uvm_swap.c        Sun May 24 14:11:49 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uvm_swap.c,v 1.192 2020/05/22 11:54:05 jdolecek Exp $  */
+/*     $NetBSD: uvm_swap.c,v 1.193 2020/05/24 14:11:49 jdolecek Exp $  */
 
 /*
  * Copyright (c) 1995, 1996, 1997, 2009 Matthew R. Green
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uvm_swap.c,v 1.192 2020/05/22 11:54:05 jdolecek Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uvm_swap.c,v 1.193 2020/05/24 14:11:49 jdolecek Exp $");
 
 #include "opt_uvmhist.h"
 #include "opt_compat_netbsd.h"
@@ -1985,7 +1985,7 @@
                 * Reads are always synchronous; if this changes, we
                 * need to add an asynchronous path for decryption.
                 */
-               KASSERT((bp->b_flags & B_READ) == 0);
+               KASSERT(write);
                return 0;
        }