From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jason L Tibbitts III , Eric Sandeen , Christoph Hellwig , "Darrick J. Wong" Subject: [PATCH 4.9 46/48] xfs: handle error if xfs_btree_get_bufs fails Date: Tue, 24 Oct 2017 15:03:59 +0200 Message-Id: <20171024125729.729177691@linuxfoundation.org> In-Reply-To: <20171024125727.668462013@linuxfoundation.org> References: <20171024125727.668462013@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Sandeen commit 93e8befc17f6d6ea92b0aee3741ceac8bca4590f upstream. 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 Signed-off-by: Greg Kroah-Hartman --- fs/xfs/libxfs/xfs_alloc.c | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/fs/xfs/libxfs/xfs_alloc.c +++ b/fs/xfs/libxfs/xfs_alloc.c @@ -1579,6 +1579,10 @@ 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; @@ -2136,6 +2140,10 @@ 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); }