INFO: task syz-executor.5:11763 blocked for more than 143 seconds. Not tainted 5.7.0-rc3-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28128 11763 7554 0x00000004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4158 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4217 __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+0x33e/0x880 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: 0033:0x416421 Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 1b 00 00 c3 48 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:0000000000c9fbe0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 000000000000000b RCX: 0000000000416421 RDX: 0000000000000000 RSI: 0000000000000bb2 RDI: 000000000000000a RBP: 0000000000000001 R08: 0000000094402bb2 R09: 0000000094402bb6 R10: 0000000000c9fcd0 R11: 0000000000000293 R12: 000000000078c900 R13: 000000000078c900 R14: ffffffffffffffff R15: 000000000078c0ec INFO: task syz-executor.3:11799 blocked for more than 143 seconds. Not tainted 5.7.0-rc3-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D28400 11799 7377 0x00004004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4158 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4217 __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+0x1e59/0x27d0 fs/namei.c:3346 do_filp_open+0x192/0x260 fs/namei.c:3373 do_sys_openat2+0x585/0x7d0 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: 0033:0x45c829 Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f8f73ca7c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00000000004f7140 RCX: 000000000045c829 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000079a R14: 00000000004ca4cf R15: 00007f8f73ca86d4 INFO: task syz-executor.4:11786 blocked for more than 143 seconds. Not tainted 5.7.0-rc3-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D27032 11786 7474 0x00004004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4158 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4217 __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+0x1e59/0x27d0 fs/namei.c:3346 do_filp_open+0x192/0x260 fs/namei.c:3373 do_sys_openat2+0x585/0x7d0 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: 0033:0x45c829 Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f2123392c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00000000004f7140 RCX: 000000000045c829 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000079a R14: 00000000004ca4cf R15: 00007f21233936d4 INFO: task syz-executor.4:11790 blocked for more than 143 seconds. Not tainted 5.7.0-rc3-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28400 11790 7474 0x00000004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4158 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4217 __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+0x1e59/0x27d0 fs/namei.c:3346 do_filp_open+0x192/0x260 fs/namei.c:3373 do_sys_openat2+0x585/0x7d0 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: 0033:0x45c829 Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f2123371c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00000000004f7140 RCX: 000000000045c829 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000079a R14: 00000000004ca4cf R15: 00007f21233726d4 Showing all locks held in the system: 1 lock held by khungtaskd/1142: #0: ffffffff899beb00 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5754 1 lock held by in:imklog/6729: #0: ffff8880a3237db0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826 5 locks held by kworker/u4:8/30188: 2 locks held by kworker/u4:12/30220: 1 lock held by syz-executor.5/11763: #0: ffff88821974b078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff88821974b078 (&fb_info->lock){+.+.}-{3:3}, at: fb_release+0x4e/0x140 drivers/video/fbdev/core/fbmem.c:1447 2 locks held by syz-executor.3/11784: 1 lock held by syz-executor.3/11799: #0: ffff88821974b078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff88821974b078 (&fb_info->lock){+.+.}-{3:3}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 1 lock held by syz-executor.4/11786: #0: ffff88821974b078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff88821974b078 (&fb_info->lock){+.+.}-{3:3}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 1 lock held by syz-executor.4/11790: #0: ffff88821974b078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff88821974b078 (&fb_info->lock){+.+.}-{3:3}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1142 Comm: khungtaskd Not tainted 5.7.0-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+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: 30220 Comm: kworker/u4:12 Not tainted 5.7.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: 0x0 (bat_events) RIP: 0010:put_pwq+0x0/0x1b0 kernel/workqueue.c:1101 Code: c7 20 c0 94 89 e8 40 61 65 00 e9 20 ff ff ff 48 c7 c7 20 c0 94 89 e8 2f 61 65 00 e9 63 ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 <55> 53 48 89 fb e8 d6 94 27 00 48 c7 c0 d4 7e 89 8a 48 ba 00 00 00 RSP: 0018:ffffc90008ecfd20 EFLAGS: 00000096 RAX: ffff88804716a400 RBX: ffff8880aa0349e8 RCX: ffffffff814b9e92 RDX: 0000000000000000 RSI: ffffffff814b9e9c RDI: ffff8880a7f4cc00 RBP: 0000000000000000 R08: ffff88804716a400 R09: ffffed1009ac020a R10: ffff88804d60104f R11: ffffed1009ac0209 R12: 0000000000000100 R13: ffff88804cc89058 R14: ffff88809e126100 R15: ffff8880aa034800 FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000160 CR3: 0000000093766000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: process_one_work+0xc20/0x16a0 kernel/workqueue.c:2310 worker_thread+0x96/0xe20 kernel/workqueue.c:2414 kthread+0x388/0x470 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352