| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.9 195/206] xfs: dont crash if reading a directory results in an unexpected hole | Date | Tue, 10 Jan 2017 14:37:58 +0100 |
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4.9-stable review patch. If anyone has any objections, please let me know.
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From: "Darrick J. Wong" <darrick.wong@oracle.com>
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> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- fs/xfs/libxfs/xfs_dir2_data.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- 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; }
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