From 5f48ab17bffc8ec4ac4425ca75530b80984e399f Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Mon, 9 Jan 2017 20:18:49 -0600 Subject: [PATCH] xfs: don't crash if reading a directory results in an unexpected hole Source kernel commit: 96a3aefb8ffde23180130460b0b2407b328eb727 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 Reviewed-by: Dave Chinner Signed-off-by: Dave Chinner Signed-off-by: Eric Sandeen --- libxfs/xfs_dir2_data.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/libxfs/xfs_dir2_data.c b/libxfs/xfs_dir2_data.c index f8def7c77..c8138968b 100644 --- a/libxfs/xfs_dir2_data.c +++ b/libxfs/xfs_dir2_data.c @@ -326,7 +326,7 @@ 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; } -- 2.47.2