From 93e8befc17f6d6ea92b0aee3741ceac8bca4590f Mon Sep 17 00:00:00 2001 From: Eric Sandeen Date: Mon, 9 Oct 2017 21:08:06 -0700 Subject: [PATCH] xfs: handle error if xfs_btree_get_bufs fails Jason reported that a corrupted filesystem failed to replay the log with a metadata block out of bounds warning: XFS (dm-2): _xfs_buf_find: Block out of range: block 0x80270fff8, EOFS 0x9c40000 _xfs_buf_find() and xfs_btree_get_bufs() return NULL if that happens, and then when xfs_alloc_fix_freelist() calls xfs_trans_binval() on that NULL bp, we oops with: BUG: unable to handle kernel NULL pointer dereference at 00000000000000f8 We don't handle _xfs_buf_find errors very well, every caller higher up the stack gets to guess at why it failed. But we should at least handle it somehow, so return EFSCORRUPTED here. Reported-by: Jason L Tibbitts III Signed-off-by: Eric Sandeen Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/xfs/libxfs/xfs_alloc.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c index 744dcaec34cca..f965ce832bc05 100644 --- a/fs/xfs/libxfs/xfs_alloc.c +++ b/fs/xfs/libxfs/xfs_alloc.c @@ -1584,6 +1584,10 @@ xfs_alloc_ag_vextent_small( bp = xfs_btree_get_bufs(args->mp, args->tp, args->agno, fbno, 0); + if (!bp) { + error = -EFSCORRUPTED; + goto error0; + } xfs_trans_binval(args->tp, bp); } args->len = 1; @@ -2141,6 +2145,10 @@ xfs_alloc_fix_freelist( if (error) goto out_agbp_relse; bp = xfs_btree_get_bufs(mp, tp, args->agno, bno, 0); + if (!bp) { + error = -EFSCORRUPTED; + goto out_agbp_relse; + } xfs_trans_binval(tp, bp); } -- 2.39.5