INFO: task syz-executor.0:23731 blocked for more than 143 seconds. Not tainted 5.14.0-rc6-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:28048 pid:23731 ppid: 12181 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4681 [inline] __schedule+0x93a/0x26f0 kernel/sched/core.c:5938 schedule+0xd3/0x270 kernel/sched/core.c:6017 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6076 __mutex_lock_common kernel/locking/mutex.c:1036 [inline] __mutex_lock+0x7b6/0x10a0 kernel/locking/mutex.c:1104 paste_selection+0x110/0x4c0 drivers/tty/vt/selection.c:390 tioclinux+0x126/0x560 drivers/tty/vt/vt.c:3164 vt_ioctl+0x225f/0x2ac0 drivers/tty/vt/vt_ioctl.c:760 tty_ioctl+0xe4d/0x1600 drivers/tty/tty_io.c:2805 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl fs/ioctl.c:1055 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:1055 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665e9 RSP: 002b:00007f8227350188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000056c038 RCX: 00000000004665e9 RDX: 0000000020000080 RSI: 000000000000541c RDI: 0000000000000005 RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c038 R13: 00007ffcc82dbdff R14: 00007f8227350300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/1655: #0: ffffffff8b97c280 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6446 1 lock held by in:imklog/8183: #0: ffff88802d04e370 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:974 2 locks held by kworker/u4:7/4742: #0: ffff888010869138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888010869138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:620 [inline] #0: ffff888010869138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888010869138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:617 [inline] #0: ffff888010869138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: ffff888010869138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x871/0x1630 kernel/workqueue.c:2247 #1: ffffc900033dfdb0 ((kfence_timer).work){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1630 kernel/workqueue.c:2251 2 locks held by agetty/11827: #0: ffff888087efc098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:252 #1: ffff888087efc2e8 (&tty->termios_rwsem){++++}-{3:3}, at: tty_set_termios+0xfe/0x910 drivers/tty/tty_ioctl.c:352 6 locks held by syz-executor.0/23730: 2 locks held by syz-executor.0/23731: #0: ffff888087efc098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:252 #1: ffff8880108790b8 (&buf->lock){+.+.}-{3:3}, at: paste_selection+0x110/0x4c0 drivers/tty/vt/selection.c:390 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1655 Comm: khungtaskd Not tainted 5.14.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0xd0a/0xfc0 kernel/hung_task.c:295 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 23730 Comm: syz-executor.0 Not tainted 5.14.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:slow_down_io arch/x86/include/asm/paravirt.h:55 [inline] RIP: 0010:outb_p arch/x86/include/asm/io.h:334 [inline] RIP: 0010:vga_io_w include/video/vga.h:209 [inline] RIP: 0010:setmode drivers/video/fbdev/vga16fb.c:125 [inline] RIP: 0010:vga_8planes_imageblit drivers/video/fbdev/vga16fb.c:1144 [inline] RIP: 0010:vga_imageblit_expand drivers/video/fbdev/vga16fb.c:1203 [inline] RIP: 0010:vga16fb_imageblit+0x1a36/0x2200 drivers/video/fbdev/vga16fb.c:1260 Code: 00 00 00 fc ff df 48 8b 54 24 28 48 c1 ea 03 80 3c 02 00 0f 85 cd 03 00 00 ff 15 f5 f9 71 07 ba cf 03 00 00 0f b6 44 24 38 ee <48> b8 00 00 00 00 00 fc ff df 48 8b 54 24 28 48 c1 ea 03 80 3c 02 RSP: 0018:ffffc90001c0f140 EFLAGS: 00000246 RAX: 00000000000000ff RBX: dffffc0000000000 RCX: ffffc900037d1000 RDX: 00000000000003cf RSI: ffffffff840d2d1c RDI: 0000000000000003 RBP: ffff8880000a0ac8 R08: 0000000000000002 R09: 0000000000000001 R10: ffffffff840d2d0e R11: 0000000000000001 R12: 0000000000000002 R13: 0000000000000007 R14: 0000000000000002 R15: ffffc90001c0f2c8 FS: 00007f8227371700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c009c0c000 CR3: 0000000068208000 CR4: 0000000000350ee0 Call Trace: bit_putcs_unaligned drivers/video/fbdev/core/bitblit.c:139 [inline] bit_putcs+0x6e1/0xd20 drivers/video/fbdev/core/bitblit.c:188 fbcon_putcs+0x35a/0x450 drivers/video/fbdev/core/fbcon.c:1296 fbcon_redraw.constprop.0+0x41a/0x4b0 drivers/video/fbdev/core/fbcon.c:1672 fbcon_scroll+0x1d7a/0x3580 drivers/video/fbdev/core/fbcon.c:1782 con_scroll+0x5b9/0x6d0 drivers/tty/vt/vt.c:630 lf+0x26b/0x2c0 drivers/tty/vt/vt.c:1490 vc_con_write_normal drivers/tty/vt/vt.c:2811 [inline] do_con_write+0xf1c/0x1e40 drivers/tty/vt/vt.c:2915 con_put_char+0x70/0xa0 drivers/tty/vt/vt.c:3263 tty_put_char+0xb7/0x150 drivers/tty/tty_io.c:3173 __process_echoes+0x15f/0x9f0 drivers/tty/n_tty.c:743 flush_echoes drivers/tty/n_tty.c:826 [inline] __receive_buf drivers/tty/n_tty.c:1579 [inline] n_tty_receive_buf_common+0x1699/0x4780 drivers/tty/n_tty.c:1674 tty_ldisc_receive_buf+0xa3/0x190 drivers/tty/tty_buffer.c:471 paste_selection+0x1de/0x4c0 drivers/tty/vt/selection.c:408 tioclinux+0x126/0x560 drivers/tty/vt/vt.c:3164 vt_ioctl+0x225f/0x2ac0 drivers/tty/vt/vt_ioctl.c:760 tty_ioctl+0xe4d/0x1600 drivers/tty/tty_io.c:2805 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl fs/ioctl.c:1055 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:1055 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665e9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f8227371188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665e9 RDX: 00000000200002c0 RSI: 000000000000541c RDI: 0000000000000005 RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffcc82dbdff R14: 00007f8227371300 R15: 0000000000022000 ---------------- Code disassembly (best guess), 5 bytes skipped: 0: df 48 8b fisttps -0x75(%rax) 3: 54 push %rsp 4: 24 28 and $0x28,%al 6: 48 c1 ea 03 shr $0x3,%rdx a: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) e: 0f 85 cd 03 00 00 jne 0x3e1 14: ff 15 f5 f9 71 07 callq *0x771f9f5(%rip) # 0x771fa0f 1a: ba cf 03 00 00 mov $0x3cf,%edx 1f: 0f b6 44 24 38 movzbl 0x38(%rsp),%eax 24: ee out %al,(%dx) * 25: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax <-- trapping instruction 2c: fc ff df 2f: 48 8b 54 24 28 mov 0x28(%rsp),%rdx 34: 48 c1 ea 03 shr $0x3,%rdx 38: 80 .byte 0x80 39: 3c 02 cmp $0x2,%al