Date: Thu, May  7 2009 11:15:56 -0500
From: Felix Blyakher <felixb@sgi.com>
References: SGI:PV995062 bnc#471396
Subject: add more checks to superblock validation
Patch-mainline: 2.6.30.5

commit 2ac00af7a6d2e65013e6f28bd1f37c0cd98ba134
Author: Olaf Weber <olaf@sgi.com>
Date: Fri Apr 17 16:12:45 2009 -0500

    xfs: add more checks to superblock validation
    
    There had been reports where xfs filesystem was randomly
    corrupted with fsfuzzer, and xfs failed to handle it
    gracefully. This patch fixes couple of reported problem
    by providing additional checks in the superblock
    validation routine.
    
Signed-off-by: Olaf Weber <olaf@sgi.com>
Reviewed-by: Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
Acked-by: <duwe@suse.de>

Index: xfs_mount.c
===========================================================================

--- a/fs/xfs/xfs_mount.c	2009-05-07 11:16:02.000000000 -0500
+++ b/fs/xfs/xfs_mount.c	2009-05-07 11:16:02.000000000 -0500
@@ -215,14 +215,17 @@ xfs_mount_validate_sb(
 	    sbp->sb_sectsize > XFS_MAX_SECTORSIZE			||
 	    sbp->sb_sectlog < XFS_MIN_SECTORSIZE_LOG			||
 	    sbp->sb_sectlog > XFS_MAX_SECTORSIZE_LOG			||
+	    sbp->sb_sectsize != (1 << sbp->sb_sectlog)			||
 	    sbp->sb_blocksize < XFS_MIN_BLOCKSIZE			||
 	    sbp->sb_blocksize > XFS_MAX_BLOCKSIZE			||
 	    sbp->sb_blocklog < XFS_MIN_BLOCKSIZE_LOG			||
 	    sbp->sb_blocklog > XFS_MAX_BLOCKSIZE_LOG			||
+	    sbp->sb_blocksize != (1 << sbp->sb_blocklog)		||
 	    sbp->sb_inodesize < XFS_DINODE_MIN_SIZE			||
 	    sbp->sb_inodesize > XFS_DINODE_MAX_SIZE			||
 	    sbp->sb_inodelog < XFS_DINODE_MIN_LOG			||
 	    sbp->sb_inodelog > XFS_DINODE_MAX_LOG			||
+	    sbp->sb_inodesize != (1 << sbp->sb_inodelog)		||
 	    (sbp->sb_blocklog - sbp->sb_inodelog != sbp->sb_inopblog)	||
 	    (sbp->sb_rextsize * sbp->sb_blocksize > XFS_MAX_RTEXTSIZE)	||
 	    (sbp->sb_rextsize * sbp->sb_blocksize < XFS_MIN_RTEXTSIZE)	||