INFO: task syz-executor.4:25657 blocked for more than 143 seconds. Not tainted 5.6.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28128 25657 7525 0x00000004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4168 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4227 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 lock_fb_info include/linux/fb.h:637 [inline] fb_release+0x4e/0x140 drivers/video/fbdev/core/fbmem.c:1447 __fput+0x2e9/0x860 fs/file_table.c:280 task_work_run+0xf4/0x1b0 kernel/task_work.c:123 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x2fa/0x360 arch/x86/entry/common.c:165 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x6b1/0x7d0 arch/x86/entry/common.c:305 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x4163e1 Code: Bad RIP value. RSP: 002b:0000000000c7fbf0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 00000000004163e1 RDX: 0000001b31b20000 RSI: 0000000000001f97 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00000000f3af3f9b R09: 00ffffffffffffff R10: 0000000000c7fcd0 R11: 0000000000000293 R12: 000000000076bf00 R13: 0000000000770b70 R14: 000000000014eff6 R15: 000000000076bf0c INFO: task syz-executor.1:25700 blocked for more than 143 seconds. Not tainted 5.6.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28128 25700 7162 0x00004006 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4168 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4227 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x219/0x5c0 fs/char_dev.c:414 do_dentry_open+0x4ba/0x1290 fs/open.c:797 do_open fs/namei.c:3229 [inline] path_openat+0x1e37/0x27b0 fs/namei.c:3346 do_filp_open+0x203/0x260 fs/namei.c:3375 do_sys_openat2+0x585/0x770 fs/open.c:1148 do_sys_open+0xc3/0x140 fs/open.c:1164 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45c849 Code: Bad RIP value. RSP: 002b:00007f9712835c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f97128366d4 RCX: 000000000045c849 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000076bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000798 R14: 00000000004ca4b4 R15: 000000000076bfac INFO: task syz-executor.2:25680 blocked for more than 143 seconds. Not tainted 5.6.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28408 25680 19610 0x00004006 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4168 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4227 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x219/0x5c0 fs/char_dev.c:414 do_dentry_open+0x4ba/0x1290 fs/open.c:797 do_open fs/namei.c:3229 [inline] path_openat+0x1e37/0x27b0 fs/namei.c:3346 do_filp_open+0x203/0x260 fs/namei.c:3375 do_sys_openat2+0x585/0x770 fs/open.c:1148 do_sys_open+0xc3/0x140 fs/open.c:1164 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45c849 Code: Bad RIP value. RSP: 002b:00007fb3de016c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fb3de0176d4 RCX: 000000000045c849 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000798 R14: 00000000004ca4b4 R15: 000000000076bf0c INFO: task syz-executor.2:25683 blocked for more than 143 seconds. Not tainted 5.6.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28408 25683 19610 0x00000006 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4168 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4227 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x219/0x5c0 fs/char_dev.c:414 do_dentry_open+0x4ba/0x1290 fs/open.c:797 do_open fs/namei.c:3229 [inline] path_openat+0x1e37/0x27b0 fs/namei.c:3346 do_filp_open+0x203/0x260 fs/namei.c:3375 do_sys_openat2+0x585/0x770 fs/open.c:1148 do_sys_open+0xc3/0x140 fs/open.c:1164 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45c849 Code: Bad RIP value. RSP: 002b:00007fb3ddff5c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fb3ddff66d4 RCX: 000000000045c849 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000076bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000798 R14: 00000000004ca4b4 R15: 000000000076bfac Showing all locks held in the system: 4 locks held by kworker/u4:2/40: 1 lock held by khungtaskd/1133: #0: ffffffff899bacc0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5743 1 lock held by systemd-udevd/4106: 1 lock held by in:imklog/6703: #0: ffff88809e0d8df0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826 3 locks held by kworker/u4:1/19805: 1 lock held by syz-executor.4/25657: #0: ffff8880a3561078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff8880a3561078 (&fb_info->lock){+.+.}-{3:3}, at: fb_release+0x4e/0x140 drivers/video/fbdev/core/fbmem.c:1447 2 locks held by syz-executor.1/25661: 1 lock held by syz-executor.1/25700: #0: ffff8880a3561078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff8880a3561078 (&fb_info->lock){+.+.}-{3:3}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 1 lock held by syz-executor.2/25680: #0: ffff8880a3561078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff8880a3561078 (&fb_info->lock){+.+.}-{3:3}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 1 lock held by syz-executor.2/25683: #0: ffff8880a3561078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff8880a3561078 (&fb_info->lock){+.+.}-{3:3}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 1 lock held by systemd-udevd/26081: 1 lock held by systemd-udevd/26084: 1 lock held by systemd-udevd/26125: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1133 Comm: khungtaskd Not tainted 5.6.0-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+0x188/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x231/0x27e lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xa8c/0x1010 kernel/hung_task.c:289 kthread+0x388/0x470 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 26125 Comm: systemd-udevd Not tainted 5.6.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x4/0x20 kernel/kcov.c:274 Code: 84 00 00 00 00 00 48 8b 0c 24 0f b7 d6 0f b7 f7 bf 03 00 00 00 e9 ec fe ff ff 66 90 66 2e 0f 1f 84 00 00 00 00 00 48 8b 0c 24 <89> f2 89 fe bf 05 00 00 00 e9 ce fe ff ff 0f 1f 40 00 66 2e 0f 1f RSP: 0018:ffffc9000e20f680 EFLAGS: 00000246 RAX: ffff888058f3c300 RBX: 0000000000000002 RCX: ffffffff83955606 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000 RBP: ffff88809ece2480 R08: ffff888058f3c300 R09: fffffbfff18fce0d R10: fffffbfff18fce0c R11: ffffffff8c7e7067 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000002 R15: ffff88809ece2480 FS: 00007ff6564068c0(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055f668edbcd0 CR3: 00000000a466c000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: check_preemption_disabled lib/smp_processor_id.c:16 [inline] debug_smp_processor_id+0x26/0x185 lib/smp_processor_id.c:57 rcu_dynticks_curr_cpu_in_eqs+0x12/0xb0 kernel/rcu/tree.c:300 rcu_is_watching+0xc/0x20 kernel/rcu/tree.c:929 rcu_read_lock_held_common+0xaf/0x130 kernel/rcu/update.c:104 rcu_read_lock_sched_held+0x5a/0xd0 kernel/rcu/update.c:119 trace_kfree include/trace/events/kmem.h:138 [inline] kfree+0x285/0x2b0 mm/slab.c:3743 tomoyo_check_open_permission+0x169/0x370 security/tomoyo/file.c:786 tomoyo_file_open security/tomoyo/tomoyo.c:319 [inline] tomoyo_file_open+0xa3/0xd0 security/tomoyo/tomoyo.c:314 security_file_open+0x6a/0x2f0 security/security.c:1548 do_dentry_open+0x358/0x1290 fs/open.c:784 do_open fs/namei.c:3229 [inline] path_openat+0x1e37/0x27b0 fs/namei.c:3346 do_filp_open+0x203/0x260 fs/namei.c:3375 do_sys_openat2+0x585/0x770 fs/open.c:1148 do_sys_open+0xc3/0x140 fs/open.c:1164 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x7ff6552796f0 Code: 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 83 3d 19 30 2c 00 00 75 10 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 fe 9d 01 00 48 89 04 24 RSP: 002b:00007ffccea31258 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff6552796f0 RDX: 0000000000000180 RSI: 00000000000800c2 RDI: 000055f668e25c60 RBP: 000000000003a2f8 R08: 000000000000fefe R09: 0000000000000030 R10: 0000000000000000 R11: 0000000000000246 R12: 000055f668e25c79 R13: 8421084210842109 R14: 00000000000800c2 R15: 00007ff655307540