From 5edf7227ec339f651c7328e63df323f6ef10345f Mon Sep 17 00:00:00 2001
From: Konstantin Belousov <kib@FreeBSD.org>
Date: Tue, 13 Apr 2021 22:48:44 +0300
Subject: [PATCH] pseudofs: limit writes to 1M

Noted and reviewed by:	markj
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D29752
---
 sys/fs/pseudofs/pseudofs_vnops.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sys/fs/pseudofs/pseudofs_vnops.c b/sys/fs/pseudofs/pseudofs_vnops.c
index e386ceba71f8..29bb1544e7ad 100644
--- a/sys/fs/pseudofs/pseudofs_vnops.c
+++ b/sys/fs/pseudofs/pseudofs_vnops.c
@@ -1102,6 +1102,9 @@ pfs_write(struct vop_write_args *va)
 	if (pn->pn_fill == NULL)
 		PFS_RETURN (EIO);
 
+	if (uio->uio_resid > PFS_MAXBUFSIZ)
+		PFS_RETURN (EIO);
+
 	/*
 	 * This is necessary because either process' privileges may
 	 * have changed since the open() call.