| From 079ebed96be2e2ef1880d7c43e9baaba0f360ac2 Mon Sep 17 00:00:00 2001 |
| From: "Darrick J. Wong" <darrick.wong@oracle.com> |
| Date: Mon, 5 Dec 2016 12:37:47 +1100 |
| Subject: [PATCH] xfs: don't crash if reading a directory results in an |
| unexpected hole |
| |
| commit 96a3aefb8ffde23180130460b0b2407b328eb727 upstream. |
| |
| In xfs_dir3_data_read, we can encounter the situation where err == 0 and |
| *bpp == NULL if the given bno offset happens to be a hole; this leads to |
| a crash if we try to set the buffer type after the _da_read_buf call. |
| Holes can happen due to corrupt or malicious entries in the bmbt data, |
| so be a little more careful when we're handling buffers. |
| |
| Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> |
| Reviewed-by: Dave Chinner <dchinner@redhat.com> |
| Signed-off-by: Dave Chinner <david@fromorbit.com> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/fs/xfs/libxfs/xfs_dir2_data.c b/fs/xfs/libxfs/xfs_dir2_data.c |
| index 725fc7841fde..e526f5a5f0be 100644 |
| --- a/fs/xfs/libxfs/xfs_dir2_data.c |
| +++ b/fs/xfs/libxfs/xfs_dir2_data.c |
| @@ -329,7 +329,7 @@ xfs_dir3_data_read( |
| |
| err = xfs_da_read_buf(tp, dp, bno, mapped_bno, bpp, |
| XFS_DATA_FORK, &xfs_dir3_data_buf_ops); |
| - if (!err && tp) |
| + if (!err && tp && *bpp) |
| xfs_trans_buf_set_type(tp, *bpp, XFS_BLFT_DIR_DATA_BUF); |
| return err; |
| } |
| -- |
| 2.10.1 |
| |
