From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:36722 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731958AbeK3BfE (ORCPT ); Thu, 29 Nov 2018 20:35:04 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+dcb8b3587445007f5808@syzkaller.appspotmail.com, Andrew Price , Bob Peterson Subject: [PATCH 4.19 035/110] gfs2: Dont leave s_fs_info pointing to freed memory in init_sbd Date: Thu, 29 Nov 2018 15:12:06 +0100 Message-Id: <20181129135922.683126717@linuxfoundation.org> In-Reply-To: <20181129135921.231283053@linuxfoundation.org> References: <20181129135921.231283053@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andrew Price commit 4c62bd9cea7bcf10292f7e4c57a2bca332942697 upstream. When alloc_percpu() fails, sdp gets freed but sb->s_fs_info still points to the same address. Move the assignment after that error check so that s_fs_info can only point to a valid sdp or NULL, which is checked for later in the error path, in gfs2_kill_super(). Reported-by: syzbot+dcb8b3587445007f5808@syzkaller.appspotmail.com Signed-off-by: Andrew Price Signed-off-by: Bob Peterson Signed-off-by: Greg Kroah-Hartman --- fs/gfs2/ops_fstype.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/gfs2/ops_fstype.c +++ b/fs/gfs2/ops_fstype.c @@ -72,13 +72,13 @@ static struct gfs2_sbd *init_sbd(struct if (!sdp) return NULL; - sb->s_fs_info = sdp; sdp->sd_vfs = sb; sdp->sd_lkstats = alloc_percpu(struct gfs2_pcpu_lkstats); if (!sdp->sd_lkstats) { kfree(sdp); return NULL; } + sb->s_fs_info = sdp; set_bit(SDF_NOJOURNALID, &sdp->sd_flags); gfs2_tune_init(&sdp->sd_tune);