> Hello, > > syzbot found the following issue on: > > HEAD commit: cea2a26553ac mailmap: Add my outdated addresses to the map.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=169fd8ee980000 > kernel config: https://syzkaller.appspot.com/x/.config?x=fa0ce06dcc735711 > dashboard link: https://syzkaller.appspot.com/bug?extid=4207adf14e7c0981d28d > compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 > > Unfortunately, I don't have any reproducer for this issue yet. > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/1f7ce933512f/disk-cea2a265.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/0ce3b9940616/vmlinux-cea2a265.xz > kernel image: https://storage.googleapis.com/syzbot-assets/19e24094ea37/bzImage-cea2a265.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+4207adf14e7c0981d28d@xxxxxxxxxxxxxxxxxxxxxxxxx > > INFO: task syz-executor.1:17770 blocked for more than 143 seconds. > Not tainted 6.10.0-rc3-syzkaller-00022-gcea2a26553ac #0 > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > task:syz-executor.1 state:D stack:23800 pid:17770 tgid:17767 ppid:11381 flags:0x00000006 > Call Trace: > <TASK> > context_switch kernel/sched/core.c:5408 [inline] > __schedule+0x17e8/0x4a20 kernel/sched/core.c:6745 > __schedule_loop kernel/sched/core.c:6822 [inline] > schedule+0x14b/0x320 kernel/sched/core.c:6837 > schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6894 > __mutex_lock_common kernel/locking/mutex.c:684 [inline] > __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752 > nfsd_nl_listener_get_doit+0x115/0x5d0 fs/nfsd/nfsctl.c:2124 > genl_family_rcv_msg_doit net/netlink/genetlink.c:1115 [inline] > genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] > genl_rcv_msg+0xb16/0xec0 net/netlink/genetlink.c:1210 > netlink_rcv_skb+0x1e5/0x430 net/netlink/af_netlink.c:2564 > genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 > netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] > netlink_unicast+0x7ec/0x980 net/netlink/af_netlink.c:1361 > netlink_sendmsg+0x8db/0xcb0 net/netlink/af_netlink.c:1905 > sock_sendmsg_nosec net/socket.c:730 [inline] > __sock_sendmsg+0x223/0x270 net/socket.c:745 > ____sys_sendmsg+0x525/0x7d0 net/socket.c:2585 > ___sys_sendmsg net/socket.c:2639 [inline] > __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2668 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 > entry_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 > > > --- > 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@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > > If the report is already addressed, let syzbot know by replying with: > #syz fix: exact-commit-title > > 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) > > If the report is a duplicate of another one, reply with: > #syz dup: exact-subject-of-another-report > > If you want to undo deduplication, reply with: > #syz undup > #syz test https://git.kernel.org/pub/scm/linux/kernel/git/cel/linux.git 4ddfda417a50 From be9676fba16c0b8769c3b6094f35da39b1ba3953 Mon Sep 17 00:00:00 2001 Message-ID: <be9676fba16c0b8769c3b6094f35da39b1ba3953.1718640518.git.lorenzo@xxxxxxxxxx> From: Lorenzo Bianconi <lorenzo@xxxxxxxxxx> Date: Mon, 17 Jun 2024 16:26:26 +0200 Subject: [PATCH] NFSD: grab nfsd_mutex in nfsd_nl_rpc_status_get_dumpit() 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: INFO: task syz-executor.1:17770 blocked for more than 143 seconds. Not tainted 6.10.0-rc3-syzkaller-00022-gcea2a26553ac #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.1 state:D stack:23800 pid:17770 tgid:17767 ppid:11381 flags:0x00000006 Call Trace: <TASK> context_switch kernel/sched/core.c:5408 [inline] __schedule+0x17e8/0x4a20 kernel/sched/core.c:6745 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6837 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6894 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752 nfsd_nl_listener_get_doit+0x115/0x5d0 fs/nfsd/nfsctl.c:2124 genl_family_rcv_msg_doit net/netlink/genetlink.c:1115 [inline] genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0xb16/0xec0 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x1e5/0x430 net/netlink/af_netlink.c:2564 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x7ec/0x980 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x8db/0xcb0 net/netlink/af_netlink.c:1905 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x223/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2585 ___sys_sendmsg net/socket.c:2639 [inline] __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2668 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_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 Fixes: 1bd773b4f0c9 ("nfsd: hold nfsd_mutex across entire netlink operation") Fixes: bd9d6a3efa97 ("NFSD: add rpc_status netlink support") Signed-off-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx> --- Documentation/netlink/specs/nfsd.yaml | 2 -- fs/nfsd/netlink.c | 2 -- fs/nfsd/netlink.h | 3 -- fs/nfsd/nfsctl.c | 48 ++++++--------------------- 4 files changed, 11 insertions(+), 44 deletions(-) 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: doc: dump pending nfsd rpc attribute-set: rpc-status dump: - pre: nfsd-nl-rpc-status-get-start - post: nfsd-nl-rpc-status-get-done reply: attributes: - 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 static const struct genl_split_ops nfsd_nl_ops[] = { { .cmd = NFSD_CMD_RPC_STATUS_GET, - .start = nfsd_nl_rpc_status_get_start, .dumpit = nfsd_nl_rpc_status_get_dumpit, - .done = nfsd_nl_rpc_status_get_done, .flags = GENL_CMD_CAP_DUMP, }, { 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 @@ extern const struct nla_policy nfsd_sock_nl_policy[NFSD_A_SOCK_TRANSPORT_NAME + 1]; extern const struct nla_policy nfsd_version_nl_policy[NFSD_A_VERSION_ENABLED + 1]; -int nfsd_nl_rpc_status_get_start(struct netlink_callback *cb); -int nfsd_nl_rpc_status_get_done(struct netlink_callback *cb); - int nfsd_nl_rpc_status_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb); int 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) unsigned int nfsd_net_id; -/** - * nfsd_nl_rpc_status_get_start - Prepare rpc_status_get dumpit - * @cb: netlink metadata and command arguments - * - * Return values: - * %0: The rpc_status_get command may proceed - * %-ENODEV: There is no NFSD running in this namespace - */ -int nfsd_nl_rpc_status_get_start(struct netlink_callback *cb) -{ - struct nfsd_net *nn = net_generic(sock_net(cb->skb->sk), nfsd_net_id); - int ret = -ENODEV; - - mutex_lock(&nfsd_mutex); - if (nn->nfsd_serv) - ret = 0; - else - mutex_unlock(&nfsd_mutex); - - return ret; -} - static int nfsd_genl_rpc_status_compose_msg(struct sk_buff *skb, struct netlink_callback *cb, struct nfsd_genl_rqstp *rqstp) @@ -1566,8 +1544,16 @@ static int nfsd_genl_rpc_status_compose_msg(struct sk_buff *skb, int nfsd_nl_rpc_status_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb) { - struct nfsd_net *nn = net_generic(sock_net(skb->sk), nfsd_net_id); int i, ret, rqstp_index = 0; + struct nfsd_net *nn; + + mutex_lock(&nfsd_mutex); + + nn = net_generic(sock_net(skb->sk), nfsd_net_id); + if (!nn->nfsd_serv) { + ret = -ENODEV; + goto out_unlock; + } rcu_read_lock(); @@ -1644,22 +1630,10 @@ int nfsd_nl_rpc_status_get_dumpit(struct sk_buff *skb, ret = skb->len; out: 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: - * %0: Success - */ -int nfsd_nl_rpc_status_get_done(struct netlink_callback *cb) -{ +out_unlock: mutex_unlock(&nfsd_mutex); - return 0; + return ret; } /** -- 2.45.1
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