INFO: task syz-executor.2:12974 blocked for more than 143 seconds. Not tainted 5.6.0-rc3-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28128 12974 11080 0x00000004 Call Trace: context_switch kernel/sched/core.c:3380 [inline] __schedule+0x934/0x1f90 kernel/sched/core.c:4080 schedule+0xdc/0x2b0 kernel/sched/core.c:4154 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4213 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118 nfnl_lock net/netfilter/nfnetlink.c:62 [inline] nfnetlink_rcv_msg+0x9ee/0xfb0 net/netfilter/nfnetlink.c:224 netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2478 nfnetlink_rcv+0x1ba/0x460 net/netfilter/nfnetlink.c:563 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0x59e/0x7e0 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x91c/0xea0 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:672 ____sys_sendmsg+0x753/0x880 net/socket.c:2343 ___sys_sendmsg+0x100/0x170 net/socket.c:2397 __sys_sendmsg+0x105/0x1d0 net/socket.c:2430 __do_sys_sendmsg net/socket.c:2439 [inline] __se_sys_sendmsg net/socket.c:2437 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2437 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c479 Code: Bad RIP value. RSP: 002b:00007f3c3b96dc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f3c3b96e6d4 RCX: 000000000045c479 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000004 RBP: 000000000076c060 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000091f R14: 00000000004cb7c5 R15: 000000000076c06c Showing all locks held in the system: 1 lock held by khungtaskd/485: #0: ffffffff89bac340 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 kernel/locking/lockdep.c:5333 2 locks held by rs:main Q:Reg/10902: #0: ffff8880a90b0120 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:821 #1: ffff888214fbc428 (sb_writers#4){.+.+}, at: file_start_write include/linux/fs.h:2903 [inline] #1: ffff888214fbc428 (sb_writers#4){.+.+}, at: vfs_write+0x485/0x5d0 fs/read_write.c:557 1 lock held by rsyslogd/10905: #0: ffff888099c8d6a0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:821 2 locks held by getty/11026: #0: ffff8880a6a4e090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900062d32e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/11027: #0: ffff888091944090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900062c32e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/11028: #0: ffff8880922f4090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900063532e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/11029: #0: ffff8880921ea090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900063432e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/11030: #0: ffff88809ada6090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900063232e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/11031: #0: ffff888095889090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900063332e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/11032: #0: ffff8880957ae090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900062932e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 3 locks held by syz-executor.2/12958: 1 lock held by syz-executor.2/12974: #0: ffffffff8c3f1750 (&table[i].mutex){+.+.}, at: nfnl_lock net/netfilter/nfnetlink.c:62 [inline] #0: ffffffff8c3f1750 (&table[i].mutex){+.+.}, at: nfnetlink_rcv_msg+0x9ee/0xfb0 net/netfilter/nfnetlink.c:224 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 485 Comm: khungtaskd Not tainted 5.6.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x197/0x210 lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x23b/0x28b lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xb11/0x10c0 kernel/hung_task.c:289 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 12958 Comm: syz-executor.2 Not tainted 5.6.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:match_held_lock+0xe/0x510 kernel/locking/lockdep.c:4012 Code: ff ff 85 c0 78 02 c9 c3 89 c7 89 45 fc e8 8a e6 ff ff 8b 45 fc c9 c3 0f 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 55 48 89 e5 <41> 57 41 56 41 55 41 54 53 48 89 fb 48 83 c7 10 48 89 fa 48 83 ec RSP: 0018:ffffc900165feeb8 EFLAGS: 00000092 RAX: dffffc0000000000 RBX: 0000000000000003 RCX: ffffc900165fef70 RDX: 0000000000000003 RSI: ffffffff89bac340 RDI: ffff88803d010e68 RBP: ffffc900165feeb8 R08: 0000000000000003 R09: ffff88803d010e10 R10: fffffbfff154b698 R11: ffffffff8aa5b4c7 R12: ffff88803d010e68 R13: ffffffff869a361a R14: ffffffff89bac340 R15: 0000000000000002 FS: 00007f3c3b9b0700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000007ff000 CR3: 00000000a2246000 CR4: 00000000001406f0 DR0: 0000000020000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: find_held_lock+0x35/0x130 kernel/locking/lockdep.c:4057 __lock_release kernel/locking/lockdep.c:4239 [inline] lock_release+0x254/0x960 kernel/locking/lockdep.c:4502 rcu_lock_release include/linux/rcupdate.h:213 [inline] rcu_read_unlock include/linux/rcupdate.h:655 [inline] cond_resched_rcu include/linux/sched.h:1798 [inline] hash_netnet4_list+0x30c/0x1400 net/netfilter/ipset/ip_set_hash_gen.h:1133 ip_set_dump_do+0xd5a/0x1b20 net/netfilter/ipset/ip_set_core.c:1632 netlink_dump+0x558/0xfb0 net/netlink/af_netlink.c:2245 __netlink_dump_start+0x673/0x930 net/netlink/af_netlink.c:2353 netlink_dump_start include/linux/netlink.h:233 [inline] ip_set_dump+0x168/0x1f0 net/netfilter/ipset/ip_set_core.c:1691 nfnetlink_rcv_msg+0xcf2/0xfb0 net/netfilter/nfnetlink.c:229 netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2478 nfnetlink_rcv+0x1ba/0x460 net/netfilter/nfnetlink.c:563 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0x59e/0x7e0 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x91c/0xea0 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:672 ____sys_sendmsg+0x753/0x880 net/socket.c:2343 ___sys_sendmsg+0x100/0x170 net/socket.c:2397 __sys_sendmsg+0x105/0x1d0 net/socket.c:2430 __do_sys_sendmsg net/socket.c:2439 [inline] __se_sys_sendmsg net/socket.c:2437 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2437 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c479 Code: Bad RIP value. RSP: 002b:00007f3c3b9afc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f3c3b9b06d4 RCX: 000000000045c479 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000004 RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000091f R14: 00000000004cb7c5 R15: 000000000076bf2c INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 0.000 msecs