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Commit d5a91bae authored by Darrick J. Wong's avatar Darrick J. Wong
Browse files

xfs: filter out obviously bad btree pointers 



Don't let anybody load an obviously bad btree pointer.  Since the values
come from disk, we must return an error, not just ASSERT.

Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: default avatarEric Sandeen <sandeen@redhat.com>
parent 7a652bbe

fs/xfs/libxfs/xfs_bmap.c

+1 −4
Original line number Diff line number Diff line
@@ -1267,7 +1267,6 @@ xfs_bmap_read_extents( 
	/* REFERENCED */

	xfs_extnum_t		room;	/* number of entries there's room for */



	bno = NULLFSBLOCK;

	mp = ip->i_mount;

	ifp = XFS_IFORK_PTR(ip, whichfork);

	exntf = (whichfork != XFS_DATA_FORK) ? XFS_EXTFMT_NOSTATE :
@@ -1280,9 +1279,7 @@ xfs_bmap_read_extents( 
	ASSERT(level > 0);

	pp = XFS_BMAP_BROOT_PTR_ADDR(mp, block, 1, ifp->if_broot_bytes);

	bno = be64_to_cpu(*pp);

	ASSERT(bno != NULLFSBLOCK);

	ASSERT(XFS_FSB_TO_AGNO(mp, bno) < mp->m_sb.sb_agcount);

	ASSERT(XFS_FSB_TO_AGBNO(mp, bno) < mp->m_sb.sb_agblocks);



	/*

	 * Go down the tree until leaf level is reached, following the first

	 * pointer (leftmost) at each level.

fs/xfs/libxfs/xfs_btree.c

+2 −1
Original line number Diff line number Diff line
@@ -826,7 +826,8 @@ xfs_btree_read_bufl( 
	xfs_daddr_t		d;		/* real disk block address */

	int			error;



	ASSERT(fsbno != NULLFSBLOCK);

	if (!XFS_FSB_SANITY_CHECK(mp, fsbno))

		return -EFSCORRUPTED;

	d = XFS_FSB_TO_DADDR(mp, fsbno);

	error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d,

				   mp->m_bsize, lock, &bp, ops);

fs/xfs/libxfs/xfs_btree.h

+1 −1
Original line number Diff line number Diff line
@@ -458,7 +458,7 @@ static inline int xfs_btree_get_level(struct xfs_btree_block *block) 
#define	XFS_FILBLKS_MAX(a,b)	max_t(xfs_filblks_t, (a), (b))



#define	XFS_FSB_SANITY_CHECK(mp,fsb)	\

	(XFS_FSB_TO_AGNO(mp, fsb) < mp->m_sb.sb_agcount && \

	(fsb && XFS_FSB_TO_AGNO(mp, fsb) < mp->m_sb.sb_agcount && \

		XFS_FSB_TO_AGBNO(mp, fsb) < mp->m_sb.sb_agblocks)



/*