From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 76BD7C433EF for ; Mon, 10 Jan 2022 18:05:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238706AbiAJSFr (ORCPT ); Mon, 10 Jan 2022 13:05:47 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:59868 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238685AbiAJSFr (ORCPT ); Mon, 10 Jan 2022 13:05:47 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 3E8C5B81052; Mon, 10 Jan 2022 18:05:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 32DAFC36AE3; Mon, 10 Jan 2022 18:05:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1641837945; bh=dnWKtHk0IMmaexsJnKOVegVsP9sJVV2kMtH9JIx/ZVM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Ckda3dbWiZftWSME3bgZNy/HtPb/AaXjsJ8L8htjUeWiT4HlZXDfLxLdIbT45Hsp+ 36dfTomFEhpnTwkyXEozdcCJVf+4dteT7eyQVhQiK2t3c8dAIJi1Pldww2n92V95b/ PAEkdqLIzQFz3/hTCdytg4P66MJGjryvZwFLf74bNksNnNudQBEpzd56AUcAx/QL3D m2KzEsVFAMLhyXBEKOVlSW4mDwQ5R1RT1P+mt7JTMUCIYWWtpLYrEv8A1IEqRIdiRc DbjeCHtyd/BCQkOrjxTR4+7f859e4CvovnEXwxgMG32zs6f8eBXWjhEN0O+soQEwI1 deOkqawUskVgQ== Date: Mon, 10 Jan 2022 20:05:40 +0200 From: Leon Romanovsky To: Jason Gunthorpe Cc: linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org, syzbot+8fcbb77276d43cc8b693@syzkaller.appspotmail.com Subject: Re: [PATCH rdma-rc] RDMA/cma: Clear all multicast request fields Message-ID: References: <1876bacbbcb6f82af3948e5c37a09da6ea3fcae5.1641474841.git.leonro@nvidia.com> <20220106173941.GA2963550@nvidia.com> <20220110153619.GC2328285@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220110153619.GC2328285@nvidia.com> Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On Mon, Jan 10, 2022 at 11:36:19AM -0400, Jason Gunthorpe wrote: > On Sun, Jan 09, 2022 at 02:22:04PM +0200, Leon Romanovsky wrote: > > On Thu, Jan 06, 2022 at 01:39:41PM -0400, Jason Gunthorpe wrote: > > > On Thu, Jan 06, 2022 at 03:15:07PM +0200, Leon Romanovsky wrote: > > > > From: Leon Romanovsky > > > > > > > > The ib->rec.qkey field is accessed without being initialized. > > > > Clear the ib_sa_multicast struct to fix the following syzkaller error/. > > > > > > > > ===================================================== > > > > BUG: KMSAN: uninit-value in cma_set_qkey drivers/infiniband/core/cma.c:510 [inline] > > > > BUG: KMSAN: uninit-value in cma_make_mc_event+0xb73/0xe00 drivers/infiniband/core/cma.c:4570 > > > > cma_set_qkey drivers/infiniband/core/cma.c:510 [inline] > > > > cma_make_mc_event+0xb73/0xe00 drivers/infiniband/core/cma.c:4570 > > > > cma_iboe_join_multicast drivers/infiniband/core/cma.c:4782 [inline] > > > > rdma_join_multicast+0x2b83/0x30a0 drivers/infiniband/core/cma.c:4814 > > > > ucma_process_join+0xa76/0xf60 drivers/infiniband/core/ucma.c:1479 > > > > ucma_join_multicast+0x1e3/0x250 drivers/infiniband/core/ucma.c:1546 > > > > ucma_write+0x639/0x6d0 drivers/infiniband/core/ucma.c:1732 > > > > vfs_write+0x8ce/0x2030 fs/read_write.c:588 > > > > ksys_write+0x28c/0x520 fs/read_write.c:643 > > > > __do_sys_write fs/read_write.c:655 [inline] > > > > __se_sys_write fs/read_write.c:652 [inline] > > > > __ia32_sys_write+0xdb/0x120 fs/read_write.c:652 > > > > do_syscall_32_irqs_on arch/x86/entry/common.c:114 [inline] > > > > __do_fast_syscall_32+0x96/0xf0 arch/x86/entry/common.c:180 > > > > do_fast_syscall_32+0x34/0x70 arch/x86/entry/common.c:205 > > > > do_SYSENTER_32+0x1b/0x20 arch/x86/entry/common.c:248 > > > > entry_SYSENTER_compat_after_hwframe+0x4d/0x5c > > > > > > > > Local variable ib.i created at: > > > > cma_iboe_join_multicast drivers/infiniband/core/cma.c:4737 [inline] > > > > rdma_join_multicast+0x586/0x30a0 drivers/infiniband/core/cma.c:4814 > > > > ucma_process_join+0xa76/0xf60 drivers/infiniband/core/ucma.c:1479 > > > > > > > > CPU: 0 PID: 29874 Comm: syz-executor.3 Not tainted 5.16.0-rc3-syzkaller #0 > > > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > > > > ===================================================== > > > > > > > > Fixes: b5de0c60cc30 ("RDMA/cma: Fix use after free race in roce multicast join") > > > > Reported-by: syzbot+8fcbb77276d43cc8b693@syzkaller.appspotmail.com > > > > Signed-off-by: Leon Romanovsky > > > > drivers/infiniband/core/cma.c | 2 +- > > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > > > diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c > > > > index 69c9a12dd14e..9c53e1e7de50 100644 > > > > +++ b/drivers/infiniband/core/cma.c > > > > @@ -4737,7 +4737,7 @@ static int cma_iboe_join_multicast(struct rdma_id_private *id_priv, > > > > int err = 0; > > > > struct sockaddr *addr = (struct sockaddr *)&mc->addr; > > > > struct net_device *ndev = NULL; > > > > - struct ib_sa_multicast ib; > > > > + struct ib_sa_multicast ib = {}; > > > > enum ib_gid_type gid_type; > > > > bool send_only; > > > > > > We shouldn't be able to join anything except a RDMA_PS_UDP to a > > > multicast in the first place: > > > > > > if (id_priv->id.ps == RDMA_PS_UDP) > > > ib.rec.qkey = cpu_to_be32(RDMA_UDP_QKEY); > > > > > > Multicast RC/etc is meaningless. So I guess it should be like this: > > > > I don't know, I used 0 exactly like we have for cma_join_ib_multicast(). > > > > Where can I read about this PS limitation? I didn't find anything > > relevant in the IBTA spec. > > It is a Linux thing > > We should probably check the PS even earlier to prevent the IB side > from having the same issue. What do you think about this? diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c index 835ac54d4a24..0a1f008ca929 100644 --- a/drivers/infiniband/core/cma.c +++ b/drivers/infiniband/core/cma.c @@ -4669,12 +4669,8 @@ static int cma_join_ib_multicast(struct rdma_id_private *id_priv, if (ret) return ret; - ret = cma_set_qkey(id_priv, 0); - if (ret) - return ret; - cma_set_mgid(id_priv, (struct sockaddr *) &mc->addr, &rec.mgid); - rec.qkey = cpu_to_be32(id_priv->qkey); + rec.qkey = cpu_to_be32(RDMA_UDP_QKEY); rdma_addr_get_sgid(dev_addr, &rec.port_gid); rec.pkey = cpu_to_be16(ib_addr_get_pkey(dev_addr)); rec.join_state = mc->join_state; @@ -4748,8 +4744,7 @@ static int cma_iboe_join_multicast(struct rdma_id_private *id_priv, cma_iboe_set_mgid(addr, &ib.rec.mgid, gid_type); ib.rec.pkey = cpu_to_be16(0xffff); - if (id_priv->id.ps == RDMA_PS_UDP) - ib.rec.qkey = cpu_to_be32(RDMA_UDP_QKEY); + ib.rec.qkey = cpu_to_be32(RDMA_UDP_QKEY); if (dev_addr->bound_dev_if) ndev = dev_get_by_index(dev_addr->net, dev_addr->bound_dev_if); @@ -4796,6 +4791,9 @@ int rdma_join_multicast(struct rdma_cm_id *id, struct sockaddr *addr, if (WARN_ON(id->qp)) return -EINVAL; + if (id->ps != RDMA_PS_UDP) + return -EINVAL; + /* ULP is calling this wrong. */ if (!id->device || (READ_ONCE(id_priv->state) != RDMA_CM_ADDR_BOUND && READ_ONCE(id_priv->state) != RDMA_CM_ADDR_RESOLVED)) > > multicast should never be used in any place that can omit a qkey, > IIRC.. > > Jason