bisecting fixing commit since c7d102232649226a69dddd58a4942cf13cff4f7c building syzkaller on 6c236867ce33c0c16b102e02a08226d7eb9b2046 testing commit c7d102232649226a69dddd58a4942cf13cff4f7c compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 3b78dda367e897f317f26e1057bdf850e34bc92a15f820e4da5bc9edb52d6ad0 all runs: crashed: INFO: task hung in synchronize_rcu testing current HEAD 4ee06de7729d795773145692e246a06448b1eb7a testing commit 4ee06de7729d795773145692e246a06448b1eb7a compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: f0144db0e73bfdbf9218895297ec28b3a195a69140461511cb0508c46301fabb run #0: crashed: INFO: task hung in synchronize_rcu run #1: crashed: INFO: task hung in synchronize_rcu run #2: crashed: INFO: task hung in synchronize_rcu run #3: crashed: INFO: task hung in __lru_add_drain_all run #4: crashed: INFO: task hung in synchronize_rcu run #5: crashed: INFO: task hung in synchronize_rcu run #6: crashed: INFO: task hung in synchronize_rcu run #7: crashed: INFO: task hung in synchronize_rcu run #8: crashed: INFO: task hung in synchronize_rcu run #9: crashed: INFO: task hung in synchronize_rcu revisions tested: 2, total time: 25m41.386327242s (build: 12m11.941567322s, test: 12m41.003066782s) the crash still happens on HEAD commit msg: net: handle ARPHRD_PIMREG in dev_is_mac_header_xmit() crash: INFO: task hung in synchronize_rcu INFO: task kworker/u4:4:1088 blocked for more than 143 seconds. Not tainted 5.17.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:4 state:D stack:27088 pid: 1088 ppid: 2 flags:0x00004000 Workqueue: events_unbound fsnotify_connector_destroy_workfn Call Trace: context_switch kernel/sched/core.c:4995 [inline] __schedule+0x90d/0x2680 kernel/sched/core.c:6304 schedule+0xd2/0x260 kernel/sched/core.c:6377 schedule_timeout+0x19d/0x250 kernel/time/timer.c:1857 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common+0x2af/0x360 kernel/sched/completion.c:106 __synchronize_srcu+0x1f2/0x290 kernel/rcu/srcutree.c:930 fsnotify_connector_destroy_workfn+0x4a/0xa0 fs/notify/mark.c:164 process_one_work+0x879/0x1410 kernel/workqueue.c:2307 process_scheduled_works kernel/workqueue.c:2370 [inline] worker_thread+0x738/0xf60 kernel/workqueue.c:2456 kthread+0x299/0x340 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 INFO: task dhcpcd:8945 blocked for more than 144 seconds. Not tainted 5.17.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:dhcpcd state:D stack:29248 pid: 8945 ppid: 3213 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:4995 [inline] __schedule+0x90d/0x2680 kernel/sched/core.c:6304 schedule+0xd2/0x260 kernel/sched/core.c:6377 exp_funnel_lock kernel/rcu/tree_exp.h:313 [inline] synchronize_rcu_expedited+0x5a8/0x620 kernel/rcu/tree_exp.h:840 synchronize_rcu+0x132/0x190 kernel/rcu/tree.c:3785 __unregister_prot_hook+0x345/0x460 net/packet/af_packet.c:382 packet_do_bind+0x629/0xa70 net/packet/af_packet.c:3210 __sys_bind+0x16b/0x1d0 net/socket.c:1697 __do_sys_bind net/socket.c:1708 [inline] __se_sys_bind net/socket.c:1706 [inline] __x64_sys_bind+0x6a/0xb0 net/socket.c:1706 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f985559cce7 RSP: 002b:00007fff8c2f1688 EFLAGS: 00000217 ORIG_RAX: 0000000000000031 RAX: ffffffffffffffda RBX: 00005559a5379b60 RCX: 00007f985559cce7 RDX: 0000000000000014 RSI: 00007fff8c2f1698 RDI: 0000000000000005 RBP: 0000000000000000 R08: 00005559a6b9bbf0 R09: 00007f985565da60 R10: 0000000000000008 R11: 0000000000000217 R12: 00005559a6b98680 R13: 00005559a6b9ce08 R14: 00007fff8c311f6c R15: 00007fff8c311f94 INFO: task dhcpcd:9062 blocked for more than 145 seconds. Not tainted 5.17.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:dhcpcd state:D stack:29248 pid: 9062 ppid: 3213 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:4995 [inline] __schedule+0x90d/0x2680 kernel/sched/core.c:6304 schedule+0xd2/0x260 kernel/sched/core.c:6377 exp_funnel_lock kernel/rcu/tree_exp.h:313 [inline] synchronize_rcu_expedited+0x5a8/0x620 kernel/rcu/tree_exp.h:840 synchronize_rcu+0x132/0x190 kernel/rcu/tree.c:3785 __unregister_prot_hook+0x345/0x460 net/packet/af_packet.c:382 packet_do_bind+0x629/0xa70 net/packet/af_packet.c:3210 __sys_bind+0x16b/0x1d0 net/socket.c:1697 __do_sys_bind net/socket.c:1708 [inline] __se_sys_bind net/socket.c:1706 [inline] __x64_sys_bind+0x6a/0xb0 net/socket.c:1706 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f985559cce7 RSP: 002b:00007fff8c2f1688 EFLAGS: 00000217 ORIG_RAX: 0000000000000031 RAX: ffffffffffffffda RBX: 00005559a5379b60 RCX: 00007f985559cce7 RDX: 0000000000000014 RSI: 00007fff8c2f1698 RDI: 0000000000000005 RBP: 0000000000000000 R08: 00005559a6b9bbf0 R09: 00007f985565da60 R10: 0000000000000010 R11: 0000000000000217 R12: 00005559a6b98680 R13: 00005559a6b9cf88 R14: 00007fff8c311f6c R15: 00007fff8c311f94 Showing all locks held in the system: 2 locks held by kworker/u4:0/8: #0: ffff88800fc69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88800fc69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff88800fc69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline] #0: ffff88800fc69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:631 [inline] #0: ffff88800fc69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:658 [inline] #0: ffff88800fc69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x79e/0x1410 kernel/workqueue.c:2278 #1: ffffc90000cd7dc0 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work+0x7cb/0x1410 kernel/workqueue.c:2282 2 locks held by ksoftirqd/0/13: 1 lock held by khungtaskd/26: #0: ffffffff8ad791e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6460 1 lock held by khugepaged/33: #0: ffffffff8ae5a648 (lock#5){+.+.}-{3:3}, at: __lru_add_drain_all+0x5a/0x6e0 mm/swap.c:798 3 locks held by kworker/1:2/141: #0: ffff88802178f938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88802178f938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff88802178f938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline] #0: ffff88802178f938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:631 [inline] #0: ffff88802178f938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:658 [inline] #0: ffff88802178f938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x79e/0x1410 kernel/workqueue.c:2278 #1: ffffc900023cfdc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7cb/0x1410 kernel/workqueue.c:2282 #2: ffffffff8c47fbc8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0x9f/0x11a0 net/ipv6/addrconf.c:4069 2 locks held by kworker/u4:4/1088: #0: ffff88800fc69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88800fc69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff88800fc69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline] #0: ffff88800fc69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:631 [inline] #0: ffff88800fc69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:658 [inline] #0: ffff88800fc69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x79e/0x1410 kernel/workqueue.c:2278 #1: ffffc900046bfdc0 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work+0x7cb/0x1410 kernel/workqueue.c:2282 1 lock held by udevd/3002: 2 locks held by getty/3307: #0: ffff88814ab1e098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x1f/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc900027632e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x9dd/0xed0 drivers/tty/n_tty.c:2075 1 lock held by syz-executor.3/3926: #0: ffff8880b9e39c18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:489 [inline] #0: ffff8880b9e39c18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock kernel/sched/sched.h:1318 [inline] #0: ffff8880b9e39c18 (&rq->__lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1616 [inline] #0: ffff8880b9e39c18 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0x236/0x2680 kernel/sched/core.c:6218 3 locks held by kworker/0:6/4196: 1 lock held by dhcpcd/8845: #0: ffff888072af5010 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:777 [inline] #0: ffff888072af5010 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release+0x76/0x270 net/socket.c:649 2 locks held by dhcpcd/8882: #0: ffff88805f906130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1668 [inline] #0: ffff88805f906130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x27/0xa70 net/packet/af_packet.c:3177 #1: ffffffff8ad82e28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #1: ffffffff8ad82e28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d5/0x620 kernel/rcu/tree_exp.h:840 1 lock held by dhcpcd/8945: #0: ffff88805fa92130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1668 [inline] #0: ffff88805fa92130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x27/0xa70 net/packet/af_packet.c:3177 1 lock held by dhcpcd/9062: #0: ffff8880724aa130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1668 [inline] #0: ffff8880724aa130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x27/0xa70 net/packet/af_packet.c:3177 1 lock held by dhcpcd/15710: #0: ffff88801c47c130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1668 [inline] #0: ffff88801c47c130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x27/0xa70 net/packet/af_packet.c:3177 1 lock held by dhcpcd/15729: #0: ffff8880605c8130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1668 [inline] #0: ffff8880605c8130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x27/0xa70 net/packet/af_packet.c:3177 1 lock held by dhcpcd/15739: #0: ffff88805364c130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1668 [inline] #0: ffff88805364c130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x27/0xa70 net/packet/af_packet.c:3177 1 lock held by dhcpcd/15829: #0: ffff88805ec2c130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1668 [inline] #0: ffff88805ec2c130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x27/0xa70 net/packet/af_packet.c:3177 1 lock held by dhcpcd/15832: #0: ffff88807e1f4130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1668 [inline] #0: ffff88807e1f4130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x27/0xa70 net/packet/af_packet.c:3177 1 lock held by dhcpcd/15851: #0: ffff88801f2ce130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1668 [inline] #0: ffff88801f2ce130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x27/0xa70 net/packet/af_packet.c:3177 2 locks held by syz-executor.4/19571: #0: ffff888054d6a610 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:777 [inline] #0: ffff888054d6a610 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release+0x76/0x270 net/socket.c:649 #1: ffffffff8c47fbc8 (rtnl_mutex){+.+.}-{3:3}, at: ip6mr_sk_done+0xad/0x2e0 net/ipv6/ip6mr.c:1580 2 locks held by syz-executor.3/19575: #0: ffff888054d69a10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:777 [inline] #0: ffff888054d69a10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release+0x76/0x270 net/socket.c:649 #1: ffffffff8c47fbc8 (rtnl_mutex){+.+.}-{3:3}, at: ip6mr_sk_done+0xad/0x2e0 net/ipv6/ip6mr.c:1580 2 locks held by syz-executor.1/19577: #0: ffff88806dbcd010 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:777 [inline] #0: ffff88806dbcd010 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release+0x76/0x270 net/socket.c:649 #1: ffff8880b9e27948 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x3e7/0x4e0 kernel/sched/psi.c:891 1 lock held by syz-executor.3/19595: 1 lock held by syz-executor.0/19600: #0: ffffffff8c47fbc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8c47fbc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x2d2/0x8d0 net/core/rtnetlink.c:5593 1 lock held by syz-executor.2/19604: #0: ffffffff8c47fbc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8c47fbc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x2d2/0x8d0 net/core/rtnetlink.c:5593 2 locks held by syz-executor.5/19598: #0: ffff888074b3fa10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:777 [inline] #0: ffff888074b3fa10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release+0x76/0x270 net/socket.c:649 #1: ffffffff8c47fbc8 (rtnl_mutex){+.+.}-{3:3}, at: ip6mr_sk_done+0xad/0x2e0 net/ipv6/ip6mr.c:1580 2 locks held by syz-executor.1/19601: #0: ffff888062f59a10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:777 [inline] #0: ffff888062f59a10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release+0x76/0x270 net/socket.c:649 #1: ffff8880b9f27948 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x3e7/0x4e0 kernel/sched/psi.c:891 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 26 Comm: khungtaskd Not tainted 5.17.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x57/0x7d lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x30/0xc0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x140/0x170 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0x88c/0xbf0 kernel/hung_task.c:369 kthread+0x299/0x340 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 13 Comm: ksoftirqd/0 Not tainted 5.17.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:fib6_check_expired include/net/ip6_fib.h:268 [inline] RIP: 0010:__find_rr_leaf+0x28c/0xa40 net/ipv6/route.c:800 Code: 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 74 08 3c 03 0f 8e a6 05 00 00 8b 44 24 0c 41 39 86 80 00 00 00 0f 85 d1 02 00 00 <4d> 8d 7e 54 4c 89 f8 48 c1 e8 03 42 0f b6 14 28 4c 89 f8 83 e0 07 RSP: 0018:ffffc90000d27570 EFLAGS: 00000246 RAX: 0000000000000100 RBX: ffff88805b2618a8 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff88ebad60 RDI: ffff888059d7c880 RBP: ffffc90000d27850 R08: 0000000000000001 R09: ffffc90000d27740 R10: fffffbfff1e1a110 R11: 0000000000000001 R12: ffffc90000d27760 R13: dffffc0000000000 R14: ffff888059d7c800 R15: ffff88805b261854 FS: 0000000000000000(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000052f7b0 CR3: 0000000045395000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: find_rr_leaf net/ipv6/route.c:847 [inline] rt6_select net/ipv6/route.c:891 [inline] fib6_table_lookup+0x496/0x840 net/ipv6/route.c:2185 ip6_pol_route+0x17d/0xe10 net/ipv6/route.c:2221 pol_lookup_func include/net/ip6_fib.h:583 [inline] fib6_rule_lookup+0xfb/0x630 net/ipv6/fib6_rules.c:115 ip6_route_input_lookup net/ipv6/route.c:2291 [inline] ip6_route_input+0x56a/0xa10 net/ipv6/route.c:2587 ip6_rcv_finish net/ipv6/ip6_input.c:74 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] ipv6_rcv+0x1b6/0x320 net/ipv6/ip6_input.c:297 __netif_receive_skb_one_core+0x104/0x180 net/core/dev.c:5351 process_backlog+0x22a/0x610 net/core/dev.c:5797 __napi_poll+0x96/0x510 net/core/dev.c:6365 napi_poll net/core/dev.c:6432 [inline] net_rx_action+0x6fc/0xa50 net/core/dev.c:6519 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 run_ksoftirqd kernel/softirq.c:921 [inline] run_ksoftirqd+0x2d/0x60 kernel/softirq.c:913 smpboot_thread_fn+0x548/0x8c0 kernel/smpboot.c:164 kthread+0x299/0x340 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: 00 48 89 add %cl,-0x77(%rax) 3: f8 clc 4: 48 c1 e8 03 shr $0x3,%rax 8: 42 0f b6 04 28 movzbl (%rax,%r13,1),%eax d: 84 c0 test %al,%al f: 74 08 je 0x19 11: 3c 03 cmp $0x3,%al 13: 0f 8e a6 05 00 00 jle 0x5bf 19: 8b 44 24 0c mov 0xc(%rsp),%eax 1d: 41 39 86 80 00 00 00 cmp %eax,0x80(%r14) 24: 0f 85 d1 02 00 00 jne 0x2fb * 2a: 4d 8d 7e 54 lea 0x54(%r14),%r15 <-- trapping instruction 2e: 4c 89 f8 mov %r15,%rax 31: 48 c1 e8 03 shr $0x3,%rax 35: 42 0f b6 14 28 movzbl (%rax,%r13,1),%edx 3a: 4c 89 f8 mov %r15,%rax 3d: 83 e0 07 and $0x7,%eax