INFO: task syz-executor.4:20112 blocked for more than 143 seconds. Not tainted 5.13.0-rc2-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:28696 pid:20112 ppid: 9062 flags:0x20004006 Call Trace: context_switch kernel/sched/core.c:4339 [inline] __schedule+0x916/0x23e0 kernel/sched/core.c:5147 schedule+0xcf/0x270 kernel/sched/core.c:5226 rwsem_down_write_slowpath+0x7e5/0x1200 kernel/locking/rwsem.c:1106 __down_write_common kernel/locking/rwsem.c:1261 [inline] __down_write_common kernel/locking/rwsem.c:1258 [inline] __down_write kernel/locking/rwsem.c:1270 [inline] down_write+0x137/0x150 kernel/locking/rwsem.c:1407 unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1949 bcm_release+0x94/0x780 net/can/bcm.c:1474 __sock_release+0xcd/0x280 net/socket.c:599 sock_close+0x18/0x20 net/socket.c:1258 __fput+0x288/0x920 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 exit_task_work include/linux/task_work.h:32 [inline] do_exit+0xbfc/0x2a60 kernel/exit.c:826 do_group_exit+0x125/0x310 kernel/exit.c:923 get_signal+0x47f/0x2150 kernel/signal.c:2818 arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:789 handle_signal_work kernel/entry/common.c:147 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x171/0x280 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:301 __do_fast_syscall_32+0x74/0xe0 arch/x86/entry/common.c:146 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:168 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c RIP: 0023:0xf7fc2549 RSP: 002b:00000000f55bc5fc EFLAGS: 00000296 ORIG_RAX: 0000000000000167 RAX: 0000000000000003 RBX: 000000000000001d RCX: 0000000000000002 RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by khungtaskd/1628: #0: ffffffff8bf792a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6333 1 lock held by in:imklog/8129: #0: ffff8880183d4af0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:974 1 lock held by syz-executor.2/28752: 3 locks held by kworker/u4:6/29284: 2 locks held by syz-executor.4/20112: #0: ffff88817bc84210 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:774 [inline] #0: ffff88817bc84210 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: __sock_release+0x86/0x280 net/socket.c:598 #1: ffffffff8d691650 (pernet_ops_rwsem){++++}-{3:3}, at: unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1949 1 lock held by syz-executor.4/20316: #0: ffffffff8d691650 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x2fa/0x760 net/core/net_namespace.c:470 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1628 Comm: khungtaskd Not tainted 5.13.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x141/0x1d7 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline] watchdog+0xd48/0xfb0 kernel/hung_task.c:294 kthread+0x3b1/0x4a0 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 488 Comm: syz-executor.2 Not tainted 5.13.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:debug_smp_processor_id+0x13/0x20 lib/smp_processor_id.c:64 Code: d3 66 bf ff e8 16 bb cd ff eb a2 66 66 2e 0f 1f 84 00 00 00 00 00 90 0f 1f 44 00 00 48 c7 c6 c0 e9 c2 89 48 c7 c7 00 ea c2 89 98 fe ff ff 0f 1f 84 00 00 00 00 00 55 48 89 fd 0f 1f 44 00 00 RSP: 0000:ffffc9001cc1fed8 EFLAGS: 00000093 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff8880629654c0 RSI: ffffffff89c2e9c0 RDI: ffffffff89c2ea00 RBP: ffff8880629654c0 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff812a965e R11: 0000000000000000 R12: ffff8880629654c0 R13: 0000000000000000 R14: 0000000000000050 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0063) knlGS:00000000f5524b40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 0000000000000050 CR3: 000000014d71d000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: fpregs_assert_state_consistent+0x65/0xe0 arch/x86/kernel/fpu/core.c:423 arch_exit_to_user_mode_prepare arch/x86/include/asm/entry-common.h:56 [inline] exit_to_user_mode_prepare+0x52/0x280 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x5/0x40 kernel/entry/common.c:314 exc_page_fault+0xc6/0x180 arch/x86/mm/fault.c:1534 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:577 RIP: 0023:0x804c520 Code: e8 15 8f 04 00 83 c4 10 85 c0 75 12 83 c4 20 5b 5e 5f c3 8d 83 e4 dd f7 ff e8 4c fb ff ff 8d 83 f2 dd f7 ff e8 41 fb ff ff 90 <53> e8 1a ec ff ff 81 c3 da fa 11 00 83 ec 08 8b 44 24 14 8b 40 0c RSP: 002b:00000000f552413c EFLAGS: 00000283 RAX: 000000000000000b RBX: 0000000000000000 RCX: 00000000f55241cc RDX: 00000000f552414c RSI: 0000000000000003 RDI: 00000000080ea4f5 RBP: 000000000819afc0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000