From: Eric Sandeen Date: Tue, 10 Oct 2017 04:08:06 +0000 (-0700) Subject: xfs: handle error if xfs_btree_get_bufs fails X-Git-Tag: v4.14-rc5~20^2 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=93e8befc17f6d6ea92b0aee3741ceac8bca4590f;p=linux.git 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 --- diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c index 744dcaec34cc..f965ce832bc0 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); }