4.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: "Darrick J. Wong" <[email protected]> commit bb3be7e7c1c18e1b141d4cadeb98cc89ecf78099 upstream. When we're reading a btree block, make sure that what we retrieved matches the owner and level; and has a plausible number of records. Signed-off-by: Darrick J. Wong <[email protected]> Reviewed-by: Dave Chinner <[email protected]> Signed-off-by: Dave Chinner <[email protected]> Cc: Christoph Hellwig <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- fs/xfs/libxfs/xfs_btree.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) --- a/fs/xfs/libxfs/xfs_btree.c +++ b/fs/xfs/libxfs/xfs_btree.c @@ -1769,8 +1769,28 @@ xfs_btree_lookup_get_block( if (error) return error; + /* Check the inode owner since the verifiers don't. */ + if (xfs_sb_version_hascrc(&cur->bc_mp->m_sb) && + (cur->bc_flags & XFS_BTREE_LONG_PTRS) && + be64_to_cpu((*blkp)->bb_u.l.bb_owner) != + cur->bc_private.b.ip->i_ino) + goto out_bad; + + /* Did we get the level we were looking for? */ + if (be16_to_cpu((*blkp)->bb_level) != level) + goto out_bad; + + /* Check that internal nodes have at least one record. */ + if (level != 0 && be16_to_cpu((*blkp)->bb_numrecs) == 0) + goto out_bad; + xfs_btree_setbuf(cur, level, bp); return 0; + +out_bad: + *blkp = NULL; + xfs_trans_brelse(cur->bc_tp, bp); + return -EFSCORRUPTED; } /*
