From e177759a416ea6ef09860382e66d9a3afc94a7fe Mon Sep 17 00:00:00 2001
From: Tom Cosgrove <tom@cvs.openbsd.org>
Date: Tue, 1 Mar 2005 14:24:34 +0000
Subject: The maximum file size on MS-DOS filesystems is 4 GB - 1 byte, so
 don't bother trying to write files bigger than this.  Just return EFBIG to
 caller, rather than panic()ing later.

Closes PR 4090.  Assistance from otto@, tested by OP and moritz@;
thanks.

ok tedu@ deraadt@
---
 sys/msdosfs/denode.h        | 5 ++++-
 sys/msdosfs/msdosfs_vnops.c | 6 +++++-
 2 files changed, 9 insertions(+), 2 deletions(-)

(limited to 'sys/msdosfs')

diff --git a/sys/msdosfs/denode.h b/sys/msdosfs/denode.h
index 14b7ccbab0d..827433ac702 100644
--- a/sys/msdosfs/denode.h
+++ b/sys/msdosfs/denode.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: denode.h,v 1.17 2004/05/14 04:05:05 tedu Exp $	*/
+/*	$OpenBSD: denode.h,v 1.18 2005/03/01 14:24:33 tom Exp $	*/
 /*	$NetBSD: denode.h,v 1.24 1997/10/17 11:23:39 ws Exp $	*/
 
 /*-
@@ -178,6 +178,9 @@ struct denode {
  */
 #define	WIN_MAXLEN	255
 
+/* Maximum size of a file on a FAT filesystem */
+#define MSDOSFS_FILESIZE_MAX	0xFFFFFFFFLL
+
 /*
  * Transfer directory entries between internal and external form.
  * dep is a struct denode * (internal form),
diff --git a/sys/msdosfs/msdosfs_vnops.c b/sys/msdosfs/msdosfs_vnops.c
index 44572722268..9fa6dad1c6a 100644
--- a/sys/msdosfs/msdosfs_vnops.c
+++ b/sys/msdosfs/msdosfs_vnops.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: msdosfs_vnops.c,v 1.49 2004/11/30 12:39:43 pedro Exp $	*/
+/*	$OpenBSD: msdosfs_vnops.c,v 1.50 2005/03/01 14:24:33 tom Exp $	*/
 /*	$NetBSD: msdosfs_vnops.c,v 1.63 1997/10/17 11:24:19 ws Exp $	*/
 
 /*-
@@ -551,6 +551,10 @@ msdosfs_write(v)
 	if (uio->uio_resid == 0)
 		return (0);
 
+	/* Don't bother to try to write files larger than the f/s limit */
+	if (uio->uio_offset + uio->uio_resid > MSDOSFS_FILESIZE_MAX)
+		return (EFBIG);
+
 	/*
 	 * If they've exceeded their filesize limit, tell them about it.
 	 */
-- 
cgit v1.2.3