From 3a3f11c990df2a56e351c829b8196b6a89f968d7 Mon Sep 17 00:00:00 2001
From: markj <markj@FreeBSD.org>
Date: Wed, 23 Oct 2019 18:00:22 +0000
Subject: [PATCH] Check for bogus_page in vnode_pager_generic_getpages_done().

We now assert that a page is busy when updating its validity-tracking
state, but bogus_page is not busied during a getpages operation.

Reported by:	syzkaller
Reviewed by:	alc, kib
Discussed with:	jeff
MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D22124
---
 sys/vm/vnode_pager.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sys/vm/vnode_pager.c b/sys/vm/vnode_pager.c
index 784c65645ada..2133449aea95 100644
--- a/sys/vm/vnode_pager.c
+++ b/sys/vm/vnode_pager.c
@@ -1149,6 +1149,8 @@ vnode_pager_generic_getpages_done(struct buf *bp)
 
 		nextoff = tfoff + PAGE_SIZE;
 		mt = bp->b_pages[i];
+		if (mt == bogus_page)
+			continue;
 
 		if (nextoff <= object->un_pager.vnp.vnp_size) {
 			/*