INFO: task syz-executor.3:20086 blocked for more than 143 seconds. Not tainted 5.7.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D29592 20086 7139 0x20024004 Call Trace: context_switch kernel/sched/core.c:3430 [inline] __schedule+0x8f3/0x1fc0 kernel/sched/core.c:4156 schedule+0xd0/0x2a0 kernel/sched/core.c:4231 schedule_timeout+0x55b/0x850 kernel/time/timer.c:1873 __down_common kernel/locking/semaphore.c:220 [inline] __down+0x176/0x2c0 kernel/locking/semaphore.c:237 down+0x57/0x80 kernel/locking/semaphore.c:61 console_lock+0x25/0x80 kernel/printk/printk.c:2331 do_fb_ioctl+0x168/0x6e0 drivers/video/fbdev/core/fbmem.c:1159 fb_compat_ioctl+0x305/0xc50 drivers/video/fbdev/core/fbmem.c:1315 __do_compat_sys_ioctl fs/ioctl.c:865 [inline] __se_compat_sys_ioctl fs/ioctl.c:816 [inline] __ia32_compat_sys_ioctl+0x23d/0x2b0 fs/ioctl.c:816 do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline] do_fast_syscall_32+0x270/0xe90 arch/x86/entry/common.c:396 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 INFO: task syz-executor.3:20102 blocked for more than 143 seconds. Not tainted 5.7.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D28064 20102 7139 0x20020004 Call Trace: context_switch kernel/sched/core.c:3430 [inline] __schedule+0x8f3/0x1fc0 kernel/sched/core.c:4156 schedule+0xd0/0x2a0 kernel/sched/core.c:4231 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4290 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7b3/0x13c0 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+0x546/0x1340 fs/open.c:828 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:1179 do_sys_open+0xc3/0x140 fs/open.c:1195 do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline] do_fast_syscall_32+0x270/0xe90 arch/x86/entry/common.c:396 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 Showing all locks held in the system: 1 lock held by khungtaskd/1145: #0: ffffffff899bdd80 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5779 4 locks held by kworker/1:2/2470: 1 lock held by in:imklog/6493: #0: ffff8880a01fb8f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826 2 locks held by syz-executor.3/20074: 1 lock held by syz-executor.3/20102: #0: ffff888218f0c078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff888218f0c078 (&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: 1145 Comm: khungtaskd Not tainted 5.7.0-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+0x1e6/0x221 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:351 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 2470 Comm: kworker/1:2 Not tainted 5.7.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events nsim_dev_trap_report_work RIP: 0010:mark_held_locks+0x82/0xe0 kernel/locking/lockdep.c:3601 Code: 57 48 63 c3 48 8d 04 80 49 8d 34 c6 48 8d 7e 22 48 89 f8 48 89 fa 48 c1 e8 03 83 e2 07 42 0f b6 04 28 38 d0 7f 04 84 c0 75 4a <0f> b6 46 22 89 c2 83 e2 03 80 fa 01 89 ea 83 da ff a8 04 74 0c 4c RSP: 0018:ffffc90007bd7b00 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000002 RSI: ffff8880a0684e90 RDI: ffff8880a0684eb2 RBP: 0000000000000002 R08: ffff8880a06845c0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880a06845c0 R13: dffffc0000000000 R14: ffff8880a0684e90 R15: ffff88803eabeec0 FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c0004a9c80 CR3: 000000009f6aa000 CR4: 00000000001426e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __trace_hardirqs_on_caller kernel/locking/lockdep.c:3627 [inline] lockdep_hardirqs_on_prepare+0x1bc/0x590 kernel/locking/lockdep.c:3686 trace_hardirqs_on+0x5f/0x230 kernel/trace/trace_preemptirq.c:49 kfree+0x1eb/0x2b0 mm/slab.c:3758 skb_free_head+0x8b/0xa0 net/core/skbuff.c:590 skb_release_data+0x42e/0x8b0 net/core/skbuff.c:610 skb_release_all+0x46/0x60 net/core/skbuff.c:664 __kfree_skb net/core/skbuff.c:678 [inline] consume_skb net/core/skbuff.c:837 [inline] consume_skb+0xf3/0x400 net/core/skbuff.c:831 nsim_dev_trap_report drivers/net/netdevsim/dev.c:573 [inline] nsim_dev_trap_report_work+0x86d/0xbc0 drivers/net/netdevsim/dev.c:598 process_one_work+0x965/0x16a0 kernel/workqueue.c:2268 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:351