mkiss: ax0: crc mode is auto. NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 INFO: task syz-executor.4:8103 blocked for more than 140 seconds. Not tainted 4.19.131-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28184 8103 6859 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x887/0x2040 kernel/sched/core.c:3515 schedule+0x8d/0x1b0 kernel/sched/core.c:3559 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3617 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x647/0x1260 kernel/locking/mutex.c:1072 fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457 chrdev_open+0x266/0x770 fs/char_dev.c:423 do_dentry_open+0x4aa/0x1160 fs/open.c:796 do_last fs/namei.c:3421 [inline] path_openat+0x793/0x2df0 fs/namei.c:3537 do_filp_open+0x18c/0x3f0 fs/namei.c:3567 do_sys_open+0x3b3/0x520 fs/open.c:1085 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45cb29 Code: 48 8b 6c 24 20 48 83 c4 28 c3 48 8b 80 c8 00 00 00 48 39 c8 74 e5 48 8b 44 24 30 48 89 04 24 48 8b 44 24 38 48 89 44 24 08 0f 44 24 48 88 44 24 10 0f b6 44 24 49 88 44 24 11 0f b6 44 24 4a RSP: 002b:00007fbc5b8e4c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00000000004f86e0 RCX: 000000000045cb29 RDX: 0000000000000000 RSI: 0000000020000040 RDI: ffffffffffffff9c RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000007c1 R14: 00000000004caafb R15: 00007fbc5b8e56d4 Showing all locks held in the system: 1 lock held by khungtaskd/1079: #0: 00000000750e0574 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4440 1 lock held by in:imklog/6104: #0: 00000000ef9825be (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767 2 locks held by agetty/6148: #0: 0000000055b4d0d0 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 0000000083d5be27 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x217/0x1950 drivers/tty/n_tty.c:2154 3 locks held by syz-executor.4/8087: 1 lock held by syz-executor.4/8103: #0: 0000000041414143 (&fb_info->lock){+.+.}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1079 Comm: khungtaskd Not tainted 4.19.131-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+0x1fc/0x2fe lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1eb lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x991/0xe60 kernel/hung_task.c:287 kthread+0x30b/0x410 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 8087 Comm: syz-executor.4 Not tainted 4.19.131-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__read_once_size include/linux/compiler.h:193 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:69 [inline] RIP: 0010:write_comp_data+0x1d/0x70 kernel/kcov.c:122 Code: d1 48 89 11 c3 0f 1f 84 00 00 00 00 00 49 89 f1 49 89 fa 65 48 8b 34 25 40 ee 01 00 65 8b 05 2a 45 98 7e a9 00 01 1f 00 75 4f <8b> 86 d8 12 00 00 83 f8 03 75 44 48 8b 86 e0 12 00 00 8b b6 dc 12 RSP: 0018:ffff8881de4e72b8 EFLAGS: 00000246 RAX: 0000000080000000 RBX: 0000000000000002 RCX: ffffffff8385d3b4 RDX: 0000000000000002 RSI: ffff888050eaa580 RDI: 0000000000000005 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000005 R11: 0000000000000000 R12: ffff8880000a0002 R13: ffff8880000a0000 R14: 0000000000000000 R15: 00000000330126c5 FS: 00007fbc5b906700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055fad1a1cae0 CR3: 00000001dcbf7000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: vga16fb_fillrect+0x9b4/0x1940 drivers/video/fbdev/vga16fb.c:922 bit_clear_margins+0x2d5/0x4a0 drivers/video/fbdev/core/bitblit.c:232 fbcon_clear_margins+0x1e2/0x350 drivers/video/fbdev/core/fbcon.c:1342 fbcon_switch+0x1038/0x1d26 drivers/video/fbdev/core/fbcon.c:2324 redraw_screen+0x37d/0x870 drivers/tty/vt/vt.c:1015 fbcon_modechanged+0x6e9/0x9f0 drivers/video/fbdev/core/fbcon.c:2972 fbcon_event_notify+0x197/0x1d80 drivers/video/fbdev/core/fbcon.c:3347 notifier_call_chain+0xc0/0x230 kernel/notifier.c:93 __blocking_notifier_call_chain kernel/notifier.c:317 [inline] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] blocking_notifier_call_chain kernel/notifier.c:328 [inline] blocking_notifier_call_chain+0x85/0xa0 kernel/notifier.c:325 fb_set_var+0xc51/0xe20 drivers/video/fbdev/core/fbmem.c:1042 do_fb_ioctl+0x3cf/0xb50 drivers/video/fbdev/core/fbmem.c:1115 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1230 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcdb/0x12e0 fs/ioctl.c:688 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45cb29 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:00007fbc5b905c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e55e0 RCX: 000000000045cb29 RDX: 0000000020000080 RSI: 0000000000004601 RDI: 0000000000000003 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000002fd R14: 00000000004c58a5 R15: 00007fbc5b9066d4