Fix overflow in superblock. From FreeBSD.

FreeBSD's log:
> The ffs superblock includes a 128-byte region for use by temporary
> in-core pointers to summary information. An array in this region
> (fs_csp) could overflow on filesystems with a very large number of
> cylinder groups (~16000 on i386 with 8k blocks). When this happens,
> other fields in the superblock get corrupted, and fsck refuses to
> check the filesystem.
>
> Solve this problem by replacing the fs_csp array in 'struct fs'
> with a single pointer, and add padding to keep the length of the
> 128-byte region fixed. Update the kernel and userland utilities
> to use just this single pointer.
>
> With this change, the kernel no longer makes use of the superblock
> fields 'fs_csshift' and 'fs_csmask'. Add a comment to newfs/mkfs.c
> to indicate that these fields must be calculated for compatibility
> with older kernels.

art@ ok.

1 files changed, 3 insertions, 3 deletions

diff --git a/sbin/fsck_ffs/utilities.c b/sbin/fsck_ffs/utilities.c
index fade9cef9b4..78a053d38e6 100644
--- a/sbin/fsck_ffs/utilities.c
+++ b/sbin/fsck_ffs/utilities.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: utilities.c,v 1.11 2001/03/02 08:33:55 art Exp $	*/
+/*	$OpenBSD: utilities.c,v 1.12 2001/04/13 02:39:05 gluk Exp $	*/
 /*	$NetBSD: utilities.c,v 1.18 1996/09/27 22:45:20 christos Exp $	*/
 
 /*
@@ -38,7 +38,7 @@
 #if 0
 static char sccsid[] = "@(#)utilities.c	8.1 (Berkeley) 6/5/93";
 #else
-static char rcsid[] = "$OpenBSD: utilities.c,v 1.11 2001/03/02 08:33:55 art Exp $";
+static char rcsid[] = "$OpenBSD: utilities.c,v 1.12 2001/04/13 02:39:05 gluk Exp $";
 #endif
 #endif /* not lint */
 
@@ -233,7 +233,7 @@ flush(fd, bp)
 	if (bp != &sblk)
 		return;
 	for (i = 0, j = 0; i < sblock.fs_cssize; i += sblock.fs_bsize, j++) {
-		bwrite(fswritefd, (char *)sblock.fs_csp[j],
+		bwrite(fswritefd, (char *)sblock.fs_csp + i,
 		    fsbtodb(&sblock, sblock.fs_csaddr + j * sblock.fs_frag),
 		    sblock.fs_cssize - i < sblock.fs_bsize ?
 		    sblock.fs_cssize - i : sblock.fs_bsize);