[PATCH 3/4] xfs: check owner of dir3 data blocks

Darrick J. Wong
2020-02-29T01:49:00Z

From: Darrick J. Wong <darrick.wong@oracle.com>

Check the owner field of dir3 data block headers.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
fs/xfs/libxfs/xfs_dir2_data.c | 32 +++++++++++++++++++++++++++++++-
1 file changed, 31 insertions(+), 1 deletion(-)

diff --git a/fs/xfs/libxfs/xfs_dir2_data.c b/fs/xfs/libxfs/xfs_dir2_data.c
index b9eba8213180..e5910bc9ab83 100644
--- a/fs/xfs/libxfs/xfs_dir2_data.c
+++ b/fs/xfs/libxfs/xfs_dir2_data.c
@@ -394,6 +394,22 @@ static const struct xfs_buf_ops xfs_dir3_data_reada_buf_ops = {
.verify_write = xfs_dir3_data_write_verify,
};

+static xfs_failaddr_t
+xfs_dir3_data_header_check(
+ struct xfs_inode *dp,
+ struct xfs_buf *bp)
+{
+ struct xfs_mount *mp = dp->i_mount;
+
+ if (xfs_sb_version_hascrc(&mp->m_sb)) {
+ struct xfs_dir3_data_hdr *hdr3 = bp->b_addr;
+
+ if (be64_to_cpu(hdr3->hdr.owner) != dp->i_ino)
+ return __this_address;
+ }
+
+ return NULL;
+}

int
xfs_dir3_data_read(
@@ -403,11 +419,25 @@ xfs_dir3_data_read(
unsigned int flags,
struct xfs_buf **bpp)
{
+ xfs_failaddr_t fa;
int err;

err = xfs_da_read_buf(tp, dp, bno, flags, bpp, XFS_DATA_FORK,
&xfs_dir3_data_buf_ops);
- if (!err && tp && *bpp)
+ if (err || !*bpp)
+ return err;
+
+ /* Check things that we can't do in the verifier. */
+ fa = xfs_dir3_data_header_check(dp, *bpp);
+ if (fa) {
+ xfs_verifier_error(*bpp, -EFSCORRUPTED, fa);
+ (*bpp)->b_flags &= ~XBF_DONE;
+ xfs_trans_brelse(tp, *bpp);
+ *bpp = NULL;
+ return -EFSCORRUPTED;
+ }
+
+ if (tp)
xfs_trans_buf_set_type(tp, *bpp, XFS_BLFT_DIR_DATA_BUF);
return err;
}