From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AA6EA29414; Mon, 17 Jun 2024 16:49:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718642999; cv=none; b=eFu2/kfcAXQpfnp6lo0ZLThVtsf1Ll2Kg/u1qTQ16HNSheM0YzGH1d0EmxX/B5qyqQnKqjnnLprtPE0ahRKJ1J1OZp5eEnHkYxh2xtVEJgCq5zLKpth7INEcm+G1Q3t9M3vXzAvlmQrqTXnk3/92v5o3h2YagfuQCuCWgnv4q7k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718642999; c=relaxed/simple; bh=xFDv5itLWWHNazNZbHJF9p1ZpfZrnLXE/9upJcBITBA=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=FYxj8BzczxCkHuItPUJmENi/6g1IU6vXyx4+gY2PNOIejzsVxSedBLSswB0WhXLTwI9JObHtWstMHAce1/D69umADPDeAdPFp5Fpjv8f6rWI7gKaTUDPpCqQaAONmbtycnPgpCYjGyuipGlGtZivRL/lQZ75jWvH0O8ZhvfM54k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=FP4GyC2D; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="FP4GyC2D" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2AB4FC2BD10; Mon, 17 Jun 2024 16:49:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1718642999; bh=xFDv5itLWWHNazNZbHJF9p1ZpfZrnLXE/9upJcBITBA=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=FP4GyC2DXPMjQQfKfSVTN7650WDP6rpnHyZYeRcHlaR0T14PQTFKKSJNAUkkMbXAN 6d4CWvLOoO/FzKZMX+GzRZHcP+gvV5W5BjyQSCwJ/jP7blh+zYP2Q5gsVRlf5h3dgR m9GEdQmrctcMsQ/5X/t8NjBZfLHY6W10Urle9nRDaMQyjs/i+QSWh/8nXzzWuE02mp U3b124GTMCh4kFYPUJ8w5z8ndRyOTGaBLEO64Gs92s6YuLzNdq0OnIoyBOwBCEKbfz /adOSi9yeSqAUrmwTcCtUlZrKk5KJe4CAY+CAWbL3hSO1aoketBTrMIG5J8EODd0Pk EjrWdsEKnUZLg== Message-ID: Subject: Re: [syzbot] [nfs?] INFO: task hung in nfsd_nl_listener_get_doit From: Jeff Layton To: Lorenzo Bianconi , syzbot Cc: Dai.Ngo@oracle.com, chuck.lever@oracle.com, kolga@netapp.com, linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org, neilb@suse.de, syzkaller-bugs@googlegroups.com, tom@talpey.com Date: Mon, 17 Jun 2024 12:49:56 -0400 In-Reply-To: References: <000000000000322bec061aeb58a3@google.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.50.4 (3.50.4-1.fc39) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Mon, 2024-06-17 at 18:26 +0200, Lorenzo Bianconi wrote: > > Hello, > >=20 > > syzbot found the following issue on: > >=20 > > HEAD commit:=C2=A0=C2=A0=C2=A0 cea2a26553ac mailmap: Add my outdated ad= dresses to > > the map.. > > git tree:=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 upstream > > console output: > > https://syzkaller.appspot.com/x/log.txt?x=3D169fd8ee980000 > > kernel config:=C2=A0 > > https://syzkaller.appspot.com/x/.config?x=3Dfa0ce06dcc735711 > > dashboard link: > > https://syzkaller.appspot.com/bug?extid=3D4207adf14e7c0981d28d > > compiler:=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 Debian clang version 15.0= .6, GNU ld (GNU Binutils > > for Debian) 2.40 > >=20 > > Unfortunately, I don't have any reproducer for this issue yet. > >=20 > > Downloadable assets: > > disk image: > > https://storage.googleapis.com/syzbot-assets/1f7ce933512f/disk-cea2a265= .raw.xz > > vmlinux: > > https://storage.googleapis.com/syzbot-assets/0ce3b9940616/vmlinux-cea2a= 265.xz > > kernel image: > > https://storage.googleapis.com/syzbot-assets/19e24094ea37/bzImage-cea2a= 265.xz > >=20 > > IMPORTANT: if you fix the issue, please add the following tag to > > the commit: > > Reported-by: syzbot+4207adf14e7c0981d28d@syzkaller.appspotmail.com > >=20 > > INFO: task syz-executor.1:17770 blocked for more than 143 seconds. > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 Not tainted 6.10.0-rc3-syzkaller-00022-g= cea2a26553ac #0 > > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this > > message. > > task:syz-executor.1=C2=A0 state:D stack:23800 pid:17770 tgid:17767 > > ppid:11381=C2=A0 flags:0x00000006 > > Call Trace: > > =C2=A0 > > =C2=A0context_switch kernel/sched/core.c:5408 [inline] > > =C2=A0__schedule+0x17e8/0x4a20 kernel/sched/core.c:6745 > > =C2=A0__schedule_loop kernel/sched/core.c:6822 [inline] > > =C2=A0schedule+0x14b/0x320 kernel/sched/core.c:6837 > > =C2=A0schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6894 > > =C2=A0__mutex_lock_common kernel/locking/mutex.c:684 [inline] > > =C2=A0__mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752 > > =C2=A0nfsd_nl_listener_get_doit+0x115/0x5d0 fs/nfsd/nfsctl.c:2124 > > =C2=A0genl_family_rcv_msg_doit net/netlink/genetlink.c:1115 [inline] > > =C2=A0genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] > > =C2=A0genl_rcv_msg+0xb16/0xec0 net/netlink/genetlink.c:1210 > > =C2=A0netlink_rcv_skb+0x1e5/0x430 net/netlink/af_netlink.c:2564 > > =C2=A0genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 > > =C2=A0netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] > > =C2=A0netlink_unicast+0x7ec/0x980 net/netlink/af_netlink.c:1361 > > =C2=A0netlink_sendmsg+0x8db/0xcb0 net/netlink/af_netlink.c:1905 > > =C2=A0sock_sendmsg_nosec net/socket.c:730 [inline] > > =C2=A0__sock_sendmsg+0x223/0x270 net/socket.c:745 > > =C2=A0____sys_sendmsg+0x525/0x7d0 net/socket.c:2585 > > =C2=A0___sys_sendmsg net/socket.c:2639 [inline] > > =C2=A0__sys_sendmsg+0x2b0/0x3a0 net/socket.c:2668 > > =C2=A0do_syscall_x64 arch/x86/entry/common.c:52 [inline] > > =C2=A0do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 > > =C2=A0entry_SYSCALL_64_after_hwframe+0x77/0x7f > > RIP: 0033:0x7f24ed27cea9 > > RSP: 002b:00007f24ee0080c8 EFLAGS: 00000246 ORIG_RAX: > > 000000000000002e > > RAX: ffffffffffffffda RBX: 00007f24ed3b3f80 RCX: 00007f24ed27cea9 > > RDX: 0000000000000000 RSI: 0000000020000100 RDI: 0000000000000005 > > RBP: 00007f24ed2ebff4 R08: 0000000000000000 R09: 0000000000000000 > > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 > >=20 > >=20 > > --- > > This report is generated by a bot. It may contain errors. > > See https://goo.gl/tpsmEJ=C2=A0for more information about syzbot. > > syzbot engineers can be reached at syzkaller@googlegroups.com. > >=20 > > syzbot will keep track of this issue. See: > > https://goo.gl/tpsmEJ#status=C2=A0for how to communicate with syzbot. > >=20 > > If the report is already addressed, let syzbot know by replying > > with: > > #syz fix: exact-commit-title > >=20 > > If you want to overwrite report's subsystems, reply with: > > #syz set subsystems: new-subsystem > > (See the list of subsystem names on the web dashboard) > >=20 > > If the report is a duplicate of another one, reply with: > > #syz dup: exact-subject-of-another-report > >=20 > > If you want to undo deduplication, reply with: > > #syz undup > >=20 >=20 > #syz test > https://git.kernel.org/pub/scm/linux/kernel/git/cel/linux.git=C2=A04ddfda= 4 > 17a50 >=20 > From be9676fba16c0b8769c3b6094f35da39b1ba3953 Mon Sep 17 00:00:00 > 2001 > Message-ID: > el.org> > From: Lorenzo Bianconi > Date: Mon, 17 Jun 2024 16:26:26 +0200 > Subject: [PATCH] NFSD: grab nfsd_mutex in > nfsd_nl_rpc_status_get_dumpit() >=20 > Grab nfsd_mutex lock in nfsd_nl_rpc_status_get_dumpit routine and > remove > nfsd_nl_rpc_status_get_start() and nfsd_nl_rpc_status_get_done(). > This > patch fix the syzbot log reported below: >=20 > INFO: task syz-executor.1:17770 blocked for more than 143 seconds. > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 Not tainted 6.10.0-rc3-syzkaller-00022-gce= a2a26553ac #0 > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this > message. > task:syz-executor.1=C2=A0 state:D stack:23800 pid:17770 tgid:17767 > ppid:11381=C2=A0 flags:0x00000006 > Call Trace: > =C2=A0 > =C2=A0context_switch kernel/sched/core.c:5408 [inline] > =C2=A0__schedule+0x17e8/0x4a20 kernel/sched/core.c:6745 > =C2=A0__schedule_loop kernel/sched/core.c:6822 [inline] > =C2=A0schedule+0x14b/0x320 kernel/sched/core.c:6837 > =C2=A0schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6894 > =C2=A0__mutex_lock_common kernel/locking/mutex.c:684 [inline] > =C2=A0__mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752 > =C2=A0nfsd_nl_listener_get_doit+0x115/0x5d0 fs/nfsd/nfsctl.c:2124 > =C2=A0genl_family_rcv_msg_doit net/netlink/genetlink.c:1115 [inline] > =C2=A0genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] > =C2=A0genl_rcv_msg+0xb16/0xec0 net/netlink/genetlink.c:1210 > =C2=A0netlink_rcv_skb+0x1e5/0x430 net/netlink/af_netlink.c:2564 > =C2=A0genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 > =C2=A0netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] > =C2=A0netlink_unicast+0x7ec/0x980 net/netlink/af_netlink.c:1361 > =C2=A0netlink_sendmsg+0x8db/0xcb0 net/netlink/af_netlink.c:1905 > =C2=A0sock_sendmsg_nosec net/socket.c:730 [inline] > =C2=A0__sock_sendmsg+0x223/0x270 net/socket.c:745 > =C2=A0____sys_sendmsg+0x525/0x7d0 net/socket.c:2585 > =C2=A0___sys_sendmsg net/socket.c:2639 [inline] > =C2=A0__sys_sendmsg+0x2b0/0x3a0 net/socket.c:2668 > =C2=A0do_syscall_x64 arch/x86/entry/common.c:52 [inline] > =C2=A0do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 > =C2=A0entry_SYSCALL_64_after_hwframe+0x77/0x7f > RIP: 0033:0x7f24ed27cea9 > RSP: 002b:00007f24ee0080c8 EFLAGS: 00000246 ORIG_RAX: > 000000000000002e > RAX: ffffffffffffffda RBX: 00007f24ed3b3f80 RCX: 00007f24ed27cea9 > RDX: 0000000000000000 RSI: 0000000020000100 RDI: 0000000000000005 > RBP: 00007f24ed2ebff4 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 >=20 > Fixes: 1bd773b4f0c9 ("nfsd: hold nfsd_mutex across entire netlink > operation") > Fixes: bd9d6a3efa97 ("NFSD: add rpc_status netlink support") > Signed-off-by: Lorenzo Bianconi > --- > =C2=A0Documentation/netlink/specs/nfsd.yaml |=C2=A0 2 -- > =C2=A0fs/nfsd/netlink.c=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 |= =C2=A0 2 -- > =C2=A0fs/nfsd/netlink.h=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 |= =C2=A0 3 -- > =C2=A0fs/nfsd/nfsctl.c=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= | 48 ++++++------------------- > -- > =C2=A04 files changed, 11 insertions(+), 44 deletions(-) >=20 > diff --git a/Documentation/netlink/specs/nfsd.yaml > b/Documentation/netlink/specs/nfsd.yaml > index 5a98e5a06c68..c87658114852 100644 > --- a/Documentation/netlink/specs/nfsd.yaml > +++ b/Documentation/netlink/specs/nfsd.yaml > @@ -132,8 +132,6 @@ operations: > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 doc: dump pending nfsd rpc > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 attribute-set: rpc-status > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 dump: > -=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 pre: nfsd-nl-rpc-status-get-s= tart > -=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 post: nfsd-nl-rpc-status-get-= done > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 reply: > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 attributes: > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 = - xid > diff --git a/fs/nfsd/netlink.c b/fs/nfsd/netlink.c > index 137701153c9e..ca54aa583530 100644 > --- a/fs/nfsd/netlink.c > +++ b/fs/nfsd/netlink.c > @@ -49,9 +49,7 @@ static const struct nla_policy > nfsd_pool_mode_set_nl_policy[NFSD_A_POOL_MODE_MOD > =C2=A0static const struct genl_split_ops nfsd_nl_ops[] =3D { > =C2=A0 { > =C2=A0 .cmd =3D NFSD_CMD_RPC_STATUS_GET, > - .start =3D nfsd_nl_rpc_status_get_start, > =C2=A0 .dumpit =3D nfsd_nl_rpc_status_get_dumpit, > - .done =3D nfsd_nl_rpc_status_get_done, > =C2=A0 .flags =3D GENL_CMD_CAP_DUMP, > =C2=A0 }, > =C2=A0 { > diff --git a/fs/nfsd/netlink.h b/fs/nfsd/netlink.h > index 9459547de04e..8eb903f24c41 100644 > --- a/fs/nfsd/netlink.h > +++ b/fs/nfsd/netlink.h > @@ -15,9 +15,6 @@ > =C2=A0extern const struct nla_policy > nfsd_sock_nl_policy[NFSD_A_SOCK_TRANSPORT_NAME + 1]; > =C2=A0extern const struct nla_policy > nfsd_version_nl_policy[NFSD_A_VERSION_ENABLED + 1]; > =C2=A0 > -int nfsd_nl_rpc_status_get_start(struct netlink_callback *cb); > -int nfsd_nl_rpc_status_get_done(struct netlink_callback *cb); > - > =C2=A0int nfsd_nl_rpc_status_get_dumpit(struct sk_buff *skb, > =C2=A0 =C2=A0 struct netlink_callback *cb); > =C2=A0int nfsd_nl_threads_set_doit(struct sk_buff *skb, struct genl_info > *info); > diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c > index e5d2cc74ef77..78091a73b33b 100644 > --- a/fs/nfsd/nfsctl.c > +++ b/fs/nfsd/nfsctl.c > @@ -1468,28 +1468,6 @@ static int create_proc_exports_entry(void) > =C2=A0 > =C2=A0unsigned int nfsd_net_id; > =C2=A0 > -/** > - * nfsd_nl_rpc_status_get_start - Prepare rpc_status_get dumpit > - * @cb: netlink metadata and command arguments > - * > - * Return values: > - *=C2=A0=C2=A0 %0: The rpc_status_get command may proceed > - *=C2=A0=C2=A0 %-ENODEV: There is no NFSD running in this namespace > - */ > -int nfsd_nl_rpc_status_get_start(struct netlink_callback *cb) > -{ > - struct nfsd_net *nn =3D net_generic(sock_net(cb->skb->sk), > nfsd_net_id); > - int ret =3D -ENODEV; > - > - mutex_lock(&nfsd_mutex); > - if (nn->nfsd_serv) > - ret =3D 0; > - else > - mutex_unlock(&nfsd_mutex); > - > - return ret; > -} > - > =C2=A0static int nfsd_genl_rpc_status_compose_msg(struct sk_buff *skb, > =C2=A0 =C2=A0=C2=A0=C2=A0 struct netlink_callback > *cb, > =C2=A0 =C2=A0=C2=A0=C2=A0 struct nfsd_genl_rqstp > *rqstp) > @@ -1566,8 +1544,16 @@ static int > nfsd_genl_rpc_status_compose_msg(struct sk_buff *skb, > =C2=A0int nfsd_nl_rpc_status_get_dumpit(struct sk_buff *skb, > =C2=A0 =C2=A0 struct netlink_callback *cb) > =C2=A0{ > - struct nfsd_net *nn =3D net_generic(sock_net(skb->sk), > nfsd_net_id); > =C2=A0 int i, ret, rqstp_index =3D 0; > + struct nfsd_net *nn; > + > + mutex_lock(&nfsd_mutex); > + > + nn =3D net_generic(sock_net(skb->sk), nfsd_net_id); > + if (!nn->nfsd_serv) { > + ret =3D -ENODEV; > + goto out_unlock; > + } > =C2=A0 > =C2=A0 rcu_read_lock(); > =C2=A0 > @@ -1644,22 +1630,10 @@ int nfsd_nl_rpc_status_get_dumpit(struct > sk_buff *skb, > =C2=A0 ret =3D skb->len; > =C2=A0out: > =C2=A0 rcu_read_unlock(); > - > - return ret; > -} > - > -/** > - * nfsd_nl_rpc_status_get_done - rpc_status_get dumpit post- > processing > - * @cb: netlink metadata and command arguments > - * > - * Return values: > - *=C2=A0=C2=A0 %0: Success > - */ > -int nfsd_nl_rpc_status_get_done(struct netlink_callback *cb) > -{ > +out_unlock: > =C2=A0 mutex_unlock(&nfsd_mutex); > =C2=A0 > - return 0; > + return ret; > =C2=A0} > =C2=A0 > =C2=A0/** Reviewed-by: Jeff Layton