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 6C2AAC4332F for ; Thu, 8 Dec 2022 09:16:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230424AbiLHJQQ (ORCPT ); Thu, 8 Dec 2022 04:16:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45292 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230406AbiLHJPx (ORCPT ); Thu, 8 Dec 2022 04:15:53 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 53A156F0D0; Thu, 8 Dec 2022 01:14:46 -0800 (PST) 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 0E644B821EB; Thu, 8 Dec 2022 09:14:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4DFB4C433C1; Thu, 8 Dec 2022 09:14:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1670490883; bh=7ugwqLbMH5I4cKEjyHD4GBrMWrGduu5H0DcZWSNKp0Y=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Nb417taWxe0OC9WHnVJ/WojSZqBpmbKUJV8t0N7saLF3OYaSaOA2o2Q4pgbZopWK/ AKwel8xKcxaM21xi8ToBSNBreuD7xSMzuKBs8BhEBI2m4mPJrKq45qNa1pgPk8r7Fk 3h4BUAzlc01E93t3rn5wZJMi5BnaxYfZEbQQasSzEmmEHkyvhojh2jz2w8nzCdo8H+ H7PSrRP1zoa8ZhWoXjY0fJZ6dbPFqd/3PbyhbBdnzzI1YC0fi+AmZrFz14YqZGebev rPTAuT5JWTKPXg+iWF3Z3VlhoabN7GeYe5DuNsnZUH4aIzdlain1lVRrmR8nfhV8Ro CjZgOkhZSL1CQ== Date: Thu, 8 Dec 2022 11:14:39 +0200 From: Leon Romanovsky To: syzbot , jgg@ziepe.ca Cc: linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org, markzhang@nvidia.com, ohartoov@nvidia.com, syzkaller-bugs@googlegroups.com Subject: Re: [syzbot] WARNING: refcount bug in nldev_newlink Message-ID: References: <0000000000004fe6c005ef43161d@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0000000000004fe6c005ef43161d@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 07, 2022 at 12:51:39PM -0800, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 591cd61541b9 Add linux-next specific files for 20221207 > git tree: linux-next > console+strace: https://syzkaller.appspot.com/x/log.txt?x=11aeafad880000 > kernel config: https://syzkaller.appspot.com/x/.config?x=8b2d3e63e054c24f > dashboard link: https://syzkaller.appspot.com/bug?extid=3fd8326d9a0812d19218 > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=112536fb880000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16aa2e6d880000 > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/bc862c01ec56/disk-591cd615.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/8f9b93f8ed2f/vmlinux-591cd615.xz > kernel image: https://storage.googleapis.com/syzbot-assets/9d5cb636d548/bzImage-591cd615.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+3fd8326d9a0812d19218@syzkaller.appspotmail.com > > WARNING: CPU: 0 PID: 5156 at lib/refcount.c:31 refcount_warn_saturate+0x1d7/0x1f0 lib/refcount.c:31 > Modules linked in: > CPU: 0 PID: 5156 Comm: syz-executor773 Not tainted 6.1.0-rc8-next-20221207-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 > RIP: 0010:refcount_warn_saturate+0x1d7/0x1f0 lib/refcount.c:31 > Code: 05 5a 60 51 0a 01 e8 35 0a b5 05 0f 0b e9 d3 fe ff ff e8 6c 9b 75 fd 48 c7 c7 c0 6d a6 8a c6 05 37 60 51 0a 01 e8 16 0a b5 05 <0f> 0b e9 b4 fe ff ff 48 89 ef e8 5a b5 c3 fd e9 5c fe ff ff 0f 1f > RSP: 0018:ffffc90003ebf0d8 EFLAGS: 00010286 > RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 > RDX: ffff88802bfcba80 RSI: ffffffff8166b1dc RDI: fffff520007d7e0d > RBP: ffff888070296600 R08: 0000000000000005 R09: 0000000000000000 > R10: 0000000080000000 R11: 0000000000000000 R12: 1ffff920007d7e20 > R13: 0000000000000000 R14: ffff888070296600 R15: ffffc90003ebf608 > FS: 000055555600f300(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007ffed185b004 CR3: 00000000265db000 CR4: 00000000003506f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > > __refcount_dec include/linux/refcount.h:344 [inline] > refcount_dec include/linux/refcount.h:359 [inline] > ref_tracker_free+0x539/0x6b0 lib/ref_tracker.c:118 > netdev_tracker_free include/linux/netdevice.h:4039 [inline] > netdev_put include/linux/netdevice.h:4056 [inline] > dev_put include/linux/netdevice.h:4082 [inline] > nldev_newlink+0x360/0x5d0 drivers/infiniband/core/nldev.c:1733 > rdma_nl_rcv_msg+0x371/0x6a0 drivers/infiniband/core/netlink.c:195 > rdma_nl_rcv_skb.constprop.0.isra.0+0x2fc/0x440 drivers/infiniband/core/netlink.c:239 > netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline] > netlink_unicast+0x547/0x7f0 net/netlink/af_netlink.c:1356 > netlink_sendmsg+0x91b/0xe10 net/netlink/af_netlink.c:1932 > sock_sendmsg_nosec net/socket.c:714 [inline] > sock_sendmsg+0xd3/0x120 net/socket.c:734 > ____sys_sendmsg+0x712/0x8c0 net/socket.c:2476 > ___sys_sendmsg+0x110/0x1b0 net/socket.c:2530 > __sys_sendmsg+0xf7/0x1c0 net/socket.c:2559 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x63/0xcd > RIP: 0033:0x7fd5bc473699 > Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 41 15 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 > RSP: 002b:00007ffed185aff8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e > RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fd5bc473699 > RDX: 0000000000000000 RSI: 0000000020000340 RDI: 0000000000000003 > RBP: 0000000000000000 R08: 000000000000000d R09: 000000000000000d > R10: 00007ffed185aa70 R11: 0000000000000246 R12: 00007ffed185b010 > R13: 00000000000f4240 R14: 0000000000011fc1 R15: 00007ffed185b004 > > > > --- > This report is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@googlegroups.com. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > syzbot can test patches for this issue, for details see: > https://goo.gl/tpsmEJ#testing-patches Jason, what do you think? diff --git a/drivers/infiniband/core/nldev.c b/drivers/infiniband/core/nldev.c index a981ac2f0975..982938c1dae3 100644 --- a/drivers/infiniband/core/nldev.c +++ b/drivers/infiniband/core/nldev.c @@ -1730,7 +1730,8 @@ static int nldev_newlink(struct sk_buff *skb, struct nlmsghdr *nlh, #endif err = ops ? ops->newlink(ibdev_name, ndev) : -EINVAL; up_read(&link_ops_rwsem); - dev_put(ndev); + if (err) + dev_put(ndev); return err; }