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: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>

diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index d3da53e6a927c3ae16de1f0c504f3c1ee8181fe3..2e91eb66d32f666d42b0dd5902ed7f2d5f66d643 100644 (file)
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -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.

diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
index 421efa0ef77880f6ed9dcf7b091411976dd531ab..c3decedc94557e14c3cb7fa7eee81d09e54f4c9e 100644 (file)
--- a/fs/xfs/libxfs/xfs_btree.c
+++ b/fs/xfs/libxfs/xfs_btree.c
@@ -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);

diff --git a/fs/xfs/libxfs/xfs_btree.h b/fs/xfs/libxfs/xfs_btree.h
index cdd4f05a59764502e22aa6091db1a6b000d083c9..4bb62580a7fd0029702b7d5092638af34b78c70b 100644 (file)
--- a/fs/xfs/libxfs/xfs_btree.h
+++ b/fs/xfs/libxfs/xfs_btree.h
@@ -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)
 
 /*