bisecting fixing commit since 2f7b98d1e55ccd34e4998bf5f321ec7b9d6b451b building syzkaller on 7e2b734bac96c22086fedd1b18135da06d5e4054 testing commit 2f7b98d1e55ccd34e4998bf5f321ec7b9d6b451b with gcc (GCC) 10.2.1 20210217 kernel signature: 6dcedb5559249ae466c589a7b7366855521d1993d96746d872cbe8313cee7ba8 all runs: crashed: INFO: task hung in misc_open testing current HEAD f88cd3fb9df228e5ce4e13ec3dbad671ddb2146e testing commit f88cd3fb9df228e5ce4e13ec3dbad671ddb2146e with gcc (GCC) 10.2.1 20210217 kernel signature: 8bb43d400848df61b2e44a4cdf7b7ed0ba4c7ceabb1cdaa97d59923b267595ae all runs: crashed: INFO: task hung in misc_open revisions tested: 2, total time: 28m30.777651732s (build: 15m16.985829466s, test: 12m35.584927428s) the crash still happens on HEAD commit msg: Merge tag 'vfio-v5.13-rc5' of git://github.com/awilliam/linux-vfio crash: INFO: task hung in misc_open INFO: task syz-executor.4:8785 blocked for more than 143 seconds. Not tainted 5.13.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:24288 pid: 8785 ppid: 1 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4339 [inline] __schedule+0x8e3/0x23a0 kernel/sched/core.c:5147 schedule+0xcf/0x270 kernel/sched/core.c:5226 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5285 __mutex_lock_common kernel/locking/mutex.c:1036 [inline] __mutex_lock+0x7d4/0x10c0 kernel/locking/mutex.c:1104 misc_open+0x50/0x410 drivers/char/misc.c:107 chrdev_open+0x20f/0x650 fs/char_dev.c:414 do_dentry_open+0x42a/0xfb0 fs/open.c:826 do_open fs/namei.c:3361 [inline] path_openat+0x9ee/0x22b0 fs/namei.c:3494 do_filp_open+0x17f/0x3a0 fs/namei.c:3521 do_sys_openat2+0x11e/0x360 fs/open.c:1187 do_sys_open fs/open.c:1203 [inline] __do_sys_openat fs/open.c:1219 [inline] __se_sys_openat fs/open.c:1214 [inline] __x64_sys_openat+0x11b/0x1d0 fs/open.c:1214 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x419544 RSP: 002b:00007fff11edf660 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fff11edfd88 RCX: 0000000000419544 RDX: 0000000000000002 RSI: 00000000004becd2 RDI: 00000000ffffff9c RBP: 00000000004becd2 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000400538 INFO: task syz-executor.3:10141 blocked for more than 143 seconds. Not tainted 5.13.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.3 state:D stack:27600 pid:10141 ppid: 8780 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4339 [inline] __schedule+0x8e3/0x23a0 kernel/sched/core.c:5147 schedule+0xcf/0x270 kernel/sched/core.c:5226 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5285 __mutex_lock_common kernel/locking/mutex.c:1036 [inline] __mutex_lock+0x7d4/0x10c0 kernel/locking/mutex.c:1104 misc_open+0x50/0x410 drivers/char/misc.c:107 chrdev_open+0x20f/0x650 fs/char_dev.c:414 do_dentry_open+0x42a/0xfb0 fs/open.c:826 do_open fs/namei.c:3361 [inline] path_openat+0x9ee/0x22b0 fs/namei.c:3494 do_filp_open+0x17f/0x3a0 fs/namei.c:3521 do_sys_openat2+0x11e/0x360 fs/open.c:1187 do_sys_open fs/open.c:1203 [inline] __do_sys_openat fs/open.c:1219 [inline] __se_sys_openat fs/open.c:1214 [inline] __x64_sys_openat+0x11b/0x1d0 fs/open.c:1214 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x466459 RSP: 002b:00007fb18340d188 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459 RDX: 0000000000020601 RSI: 00000000200003c0 RDI: ffffffffffffff9c RBP: 00000000004bf9fb R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007fff2bebcd5f R14: 00007fb18340d300 R15: 0000000000022000 INFO: task syz-executor.3:10256 blocked for more than 143 seconds. Not tainted 5.13.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.3 state:D stack:28520 pid:10256 ppid: 8780 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4339 [inline] __schedule+0x8e3/0x23a0 kernel/sched/core.c:5147 schedule+0xcf/0x270 kernel/sched/core.c:5226 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5285 __mutex_lock_common kernel/locking/mutex.c:1036 [inline] __mutex_lock+0x7d4/0x10c0 kernel/locking/mutex.c:1104 misc_open+0x50/0x410 drivers/char/misc.c:107 chrdev_open+0x20f/0x650 fs/char_dev.c:414 do_dentry_open+0x42a/0xfb0 fs/open.c:826 do_open fs/namei.c:3361 [inline] path_openat+0x9ee/0x22b0 fs/namei.c:3494 do_filp_open+0x17f/0x3a0 fs/namei.c:3521 do_sys_openat2+0x11e/0x360 fs/open.c:1187 do_sys_open fs/open.c:1203 [inline] __do_sys_openat fs/open.c:1219 [inline] __se_sys_openat fs/open.c:1214 [inline] __x64_sys_openat+0x11b/0x1d0 fs/open.c:1214 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x419544 RSP: 002b:00007fb1833ea040 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 0000000000419544 RDX: 0000000000000002 RSI: 00000000004be78a RDI: 00000000ffffff9c RBP: 00000000004be78a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000020001940 R15: 0000000000022000 INFO: task syz-executor.0:10159 blocked for more than 144 seconds. Not tainted 5.13.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:27600 pid:10159 ppid: 8790 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4339 [inline] __schedule+0x8e3/0x23a0 kernel/sched/core.c:5147 schedule+0xcf/0x270 kernel/sched/core.c:5226 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5285 __mutex_lock_common kernel/locking/mutex.c:1036 [inline] __mutex_lock+0x7d4/0x10c0 kernel/locking/mutex.c:1104 misc_open+0x50/0x410 drivers/char/misc.c:107 chrdev_open+0x20f/0x650 fs/char_dev.c:414 do_dentry_open+0x42a/0xfb0 fs/open.c:826 do_open fs/namei.c:3361 [inline] path_openat+0x9ee/0x22b0 fs/namei.c:3494 do_filp_open+0x17f/0x3a0 fs/namei.c:3521 do_sys_openat2+0x11e/0x360 fs/open.c:1187 do_sys_open fs/open.c:1203 [inline] __do_sys_openat fs/open.c:1219 [inline] __se_sys_openat fs/open.c:1214 [inline] __x64_sys_openat+0x11b/0x1d0 fs/open.c:1214 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x419544 RSP: 002b:00007f47da1b8040 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000419544 RDX: 0000000000000002 RSI: 00000000004be78a RDI: 00000000ffffff9c RBP: 00000000004be78a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000020000440 R15: 0000000000022000 INFO: task syz-executor.1:10184 blocked for more than 144 seconds. Not tainted 5.13.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.1 state:D stack:27600 pid:10184 ppid: 8788 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4339 [inline] __schedule+0x8e3/0x23a0 kernel/sched/core.c:5147 schedule+0xcf/0x270 kernel/sched/core.c:5226 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5285 __mutex_lock_common kernel/locking/mutex.c:1036 [inline] __mutex_lock+0x7d4/0x10c0 kernel/locking/mutex.c:1104 misc_open+0x50/0x410 drivers/char/misc.c:107 chrdev_open+0x20f/0x650 fs/char_dev.c:414 do_dentry_open+0x42a/0xfb0 fs/open.c:826 do_open fs/namei.c:3361 [inline] path_openat+0x9ee/0x22b0 fs/namei.c:3494 do_filp_open+0x17f/0x3a0 fs/namei.c:3521 do_sys_openat2+0x11e/0x360 fs/open.c:1187 do_sys_open fs/open.c:1203 [inline] __do_sys_openat fs/open.c:1219 [inline] __se_sys_openat fs/open.c:1214 [inline] __x64_sys_openat+0x11b/0x1d0 fs/open.c:1214 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x419544 RSP: 002b:00007fd135e98040 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000419544 RDX: 0000000000000002 RSI: 00000000004be78a RDI: 00000000ffffff9c RBP: 00000000004be78a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000020000440 R15: 0000000000022000 INFO: task syz-executor.2:10243 blocked for more than 144 seconds. Not tainted 5.13.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.2 state:D stack:27600 pid:10243 ppid: 8786 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4339 [inline] __schedule+0x8e3/0x23a0 kernel/sched/core.c:5147 schedule+0xcf/0x270 kernel/sched/core.c:5226 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5285 __mutex_lock_common kernel/locking/mutex.c:1036 [inline] __mutex_lock+0x7d4/0x10c0 kernel/locking/mutex.c:1104 misc_open+0x50/0x410 drivers/char/misc.c:107 chrdev_open+0x20f/0x650 fs/char_dev.c:414 do_dentry_open+0x42a/0xfb0 fs/open.c:826 do_open fs/namei.c:3361 [inline] path_openat+0x9ee/0x22b0 fs/namei.c:3494 do_filp_open+0x17f/0x3a0 fs/namei.c:3521 do_sys_openat2+0x11e/0x360 fs/open.c:1187 do_sys_open fs/open.c:1203 [inline] __do_sys_openat fs/open.c:1219 [inline] __se_sys_openat fs/open.c:1214 [inline] __x64_sys_openat+0x11b/0x1d0 fs/open.c:1214 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x419544 RSP: 002b:00007fd73b574040 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 0000000000419544 RDX: 0000000000000002 RSI: 00000000004be78a RDI: 00000000ffffff9c RBP: 00000000004be78a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000020001940 R15: 0000000000022000 INFO: task syz-executor.5:10253 blocked for more than 145 seconds. Not tainted 5.13.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.5 state:D stack:27600 pid:10253 ppid: 8789 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4339 [inline] __schedule+0x8e3/0x23a0 kernel/sched/core.c:5147 schedule+0xcf/0x270 kernel/sched/core.c:5226 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5285 __mutex_lock_common kernel/locking/mutex.c:1036 [inline] __mutex_lock+0x7d4/0x10c0 kernel/locking/mutex.c:1104 misc_open+0x50/0x410 drivers/char/misc.c:107 chrdev_open+0x20f/0x650 fs/char_dev.c:414 do_dentry_open+0x42a/0xfb0 fs/open.c:826 do_open fs/namei.c:3361 [inline] path_openat+0x9ee/0x22b0 fs/namei.c:3494 do_filp_open+0x17f/0x3a0 fs/namei.c:3521 do_sys_openat2+0x11e/0x360 fs/open.c:1187 do_sys_open fs/open.c:1203 [inline] __do_sys_openat fs/open.c:1219 [inline] __se_sys_openat fs/open.c:1214 [inline] __x64_sys_openat+0x11b/0x1d0 fs/open.c:1214 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x466459 RSP: 002b:00007f8db817e188 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459 RDX: 0000000000020601 RSI: 00000000200003c0 RDI: ffffffffffffff9c RBP: 00000000004bf9fb R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007fffd3fa40ff R14: 00007f8db817e300 R15: 0000000000022000 INFO: task syz-executor.5:10258 blocked for more than 145 seconds. Not tainted 5.13.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.5 state:D stack:27464 pid:10258 ppid: 8789 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4339 [inline] __schedule+0x8e3/0x23a0 kernel/sched/core.c:5147 schedule+0xcf/0x270 kernel/sched/core.c:5226 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5285 __mutex_lock_common kernel/locking/mutex.c:1036 [inline] __mutex_lock+0x7d4/0x10c0 kernel/locking/mutex.c:1104 misc_open+0x50/0x410 drivers/char/misc.c:107 chrdev_open+0x20f/0x650 fs/char_dev.c:414 do_dentry_open+0x42a/0xfb0 fs/open.c:826 do_open fs/namei.c:3361 [inline] path_openat+0x9ee/0x22b0 fs/namei.c:3494 do_filp_open+0x17f/0x3a0 fs/namei.c:3521 do_sys_openat2+0x11e/0x360 fs/open.c:1187 do_sys_open fs/open.c:1203 [inline] __do_sys_openat fs/open.c:1219 [inline] __se_sys_openat fs/open.c:1214 [inline] __x64_sys_openat+0x11b/0x1d0 fs/open.c:1214 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x419544 RSP: 002b:00007f8db815b040 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 0000000000419544 RDX: 0000000000000002 RSI: 00000000004be78a RDI: 00000000ffffff9c RBP: 00000000004be78a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000020001940 R15: 0000000000022000 Showing all locks held in the system: 3 locks held by kworker/u4:1/25: #0: ffff8880ba135618 (&rq->lock){-.-.}-{2:2}, at: newidle_balance+0x801/0xe60 kernel/sched/fair.c:10665 #1: ffff8880ba11f988 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x24c/0x670 kernel/sched/psi.c:872 #2: ffff8880ba124218 (&base->lock){..-.}-{2:2}, at: lock_timer_base+0x49/0x1a0 kernel/time/timer.c:944 1 lock held by khungtaskd/1511: #0: ffffffff8a96ff00 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6333 5 locks held by kworker/1:2/2941: #0: ffff88814106a138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88814106a138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff88814106a138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff88814106a138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:617 [inline] #0: ffff88814106a138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: ffff88814106a138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x771/0x13b0 kernel/workqueue.c:2247 #1: ffffc9000239fdb0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79e/0x13b0 kernel/workqueue.c:2251 #2: ffff888143270220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:742 [inline] #2: ffff888143270220 (&dev->mutex){....}-{3:3}, at: hub_event+0x127/0x36d0 drivers/usb/core/hub.c:5590 #3: ffff88801ce95220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:742 [inline] #3: ffff88801ce95220 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x410 drivers/base/dd.c:913 #4: ffff8880328271a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:742 [inline] #4: ffff8880328271a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x410 drivers/base/dd.c:913 1 lock held by in:imklog/8107: #0: ffff88801c156af0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x9c/0xb0 fs/file.c:974 1 lock held by syz-executor.4/8785: #0: ffffffff8b350c88 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x50/0x410 drivers/char/misc.c:107 5 locks held by kworker/1:7/10085: #0: ffff88814106a138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88814106a138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff88814106a138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff88814106a138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:617 [inline] #0: ffff88814106a138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: ffff88814106a138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x771/0x13b0 kernel/workqueue.c:2247 #1: ffffc9000b0a7db0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79e/0x13b0 kernel/workqueue.c:2251 #2: ffff88801bfb8220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:742 [inline] #2: ffff88801bfb8220 (&dev->mutex){....}-{3:3}, at: hub_event+0x127/0x36d0 drivers/usb/core/hub.c:5590 #3: ffff888032823220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:742 [inline] #3: ffff888032823220 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x410 drivers/base/dd.c:913 #4: ffff8880285d21a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:742 [inline] #4: ffff8880285d21a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x74/0x410 drivers/base/dd.c:913 1 lock held by syz-executor.3/10141: #0: ffffffff8b350c88 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x50/0x410 drivers/char/misc.c:107 1 lock held by syz-executor.3/10256: #0: ffffffff8b350c88 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x50/0x410 drivers/char/misc.c:107 1 lock held by syz-executor.0/10159: #0: ffffffff8b350c88 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x50/0x410 drivers/char/misc.c:107 1 lock held by syz-executor.1/10184: #0: ffffffff8b350c88 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x50/0x410 drivers/char/misc.c:107 2 locks held by syz-executor.2/10237: #0: ffffffff8b350c88 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x50/0x410 drivers/char/misc.c:107 #1: ffffffff8a8411c8 (system_transition_mutex){+.+.}-{3:3}, at: snapshot_open+0x1c/0x210 kernel/power/user.c:54 1 lock held by syz-executor.2/10243: #0: ffffffff8b350c88 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x50/0x410 drivers/char/misc.c:107 1 lock held by syz-executor.5/10253: #0: ffffffff8b350c88 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x50/0x410 drivers/char/misc.c:107 1 lock held by syz-executor.5/10258: #0: ffffffff8b350c88 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x50/0x410 drivers/char/misc.c:107 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1511 Comm: khungtaskd Not tainted 5.13.0-rc4-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+0xa5/0xe6 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x30/0x99 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x11f/0x170 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+0x956/0xc30 kernel/hung_task.c:294 kthread+0x36f/0x450 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: 48 Comm: kworker/u4:3 Not tainted 5.13.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: phy6 ieee80211_iface_work RIP: 0010:hlock_class kernel/locking/lockdep.c:194 [inline] RIP: 0010:mark_lock+0xcd/0x1840 kernel/locking/lockdep.c:4458 Code: 4d 8d 7d 20 48 b8 00 00 00 00 00 fc ff df 4c 89 fa 48 c1 ea 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e 6a 08 00 00 41 0f b7 55 20 <66> 81 e2 ff 1f 44 0f b7 f2 be 08 00 00 00 4c 89 f0 48 c1 f8 06 48 RSP: 0018:ffffc90000eff288 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 1ffff920001dfe57 RCX: 0000000000000008 RDX: 0000000000000714 RSI: ffff888010708a70 RDI: ffff888010708a92 RBP: 0000000000000100 R08: 0000000000000000 R09: ffffffff8e429987 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000008 R13: ffff888010708a70 R14: 0000000000000003 R15: ffff888010708a90 FS: 0000000000000000(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8eeff04000 CR3: 000000001292a000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: mark_usage kernel/locking/lockdep.c:4401 [inline] __lock_acquire+0x8e4/0x5560 kernel/locking/lockdep.c:4856 lock_acquire kernel/locking/lockdep.c:5512 [inline] lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5477 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:175 spin_lock_bh include/linux/spinlock.h:359 [inline] cfg80211_put_bss+0x2b/0x1e0 net/wireless/scan.c:2501 ieee80211_rx_bss_info net/mac80211/ibss.c:1198 [inline] ieee80211_rx_mgmt_probe_beacon+0x891/0x15e0 net/mac80211/ibss.c:1615 ieee80211_ibss_rx_queued_mgmt+0xb85/0x14c0 net/mac80211/ibss.c:1642 ieee80211_iface_work+0x565/0x7b0 net/mac80211/iface.c:1437 process_one_work+0x84c/0x13b0 kernel/workqueue.c:2276 worker_thread+0x598/0xf80 kernel/workqueue.c:2422 kthread+0x36f/0x450 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294