syzbot

INFO: task syz-executor.5:1185 blocked for more than 143 seconds.
      Not tainted 5.11.0-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.5  state:D stack:28520 pid: 1185 ppid: 10968 flags:0x20004004
Call Trace:
 context_switch kernel/sched/core.c:4327 [inline]
 __schedule+0x90c/0x21a0 kernel/sched/core.c:5078
 schedule+0xcf/0x270 kernel/sched/core.c:5157
 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1854
 __down_common kernel/locking/semaphore.c:220 [inline]
 __down+0x183/0x2a0 kernel/locking/semaphore.c:237
 down+0x57/0x80 kernel/locking/semaphore.c:61
 console_lock+0x25/0x80 kernel/printk/printk.c:2387
 vcs_open+0x62/0xc0 drivers/tty/vt/vc_screen.c:756
 chrdev_open+0x266/0x770 fs/char_dev.c:414
 do_dentry_open+0x4b9/0x11b0 fs/open.c:817
 do_open fs/namei.c:3254 [inline]
 path_openat+0x1b9a/0x2730 fs/namei.c:3371
 do_filp_open+0x17e/0x3c0 fs/namei.c:3398
 do_sys_openat2+0x16d/0x420 fs/open.c:1172
 do_sys_open fs/open.c:1188 [inline]
 __do_compat_sys_openat fs/open.c:1246 [inline]
 __se_compat_sys_openat fs/open.c:1244 [inline]
 __ia32_compat_sys_openat+0x13f/0x1f0 fs/open.c:1244
 do_syscall_32_irqs_on arch/x86/entry/common.c:77 [inline]
 __do_fast_syscall_32+0x56/0x80 arch/x86/entry/common.c:139
 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:164
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
RIP: 0023:0xf7f2e549
RSP: 002b:00000000f55071a0 EFLAGS: 00000282 ORIG_RAX: 0000000000000127
RAX: ffffffffffffffda RBX: 00000000ffffff9c RCX: 00000000f55071f0
RDX: 0000000000040c01 RSI: 0000000000000000 RDI: 0000000008167000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Showing all locks held in the system:
1 lock held by khungtaskd/1651:
 #0: ffffffff8bf721a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6259
1 lock held by systemd-journal/4863:
1 lock held by in:imklog/8148:
 #0: ffff8880129165f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:947
2 locks held by agetty/30398:
 #0: ffff88801be9a098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:266
 #1: ffffc900022342e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xd5b/0x12f0 drivers/tty/n_tty.c:2178
1 lock held by syz-executor.2/30701:
1 lock held by syz-executor.5/1058:

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 1651 Comm: khungtaskd Not tainted 5.11.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0xfa/0x151 lib/dump_stack.c:120
 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:209 [inline]
 watchdog+0xd43/0xfa0 kernel/hung_task.c:294
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 30701 Comm: syz-executor.2 Not tainted 5.11.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:unwind_next_frame+0x1cf/0x1f90 arch/x86/kernel/unwind_orc.c:443
Code: 41 0f b6 47 35 48 ba 00 00 00 00 00 fc ff df 48 c1 e9 03 80 3c 11 00 0f 85 6e 15 00 00 49 8b 4f 48 3c 01 49 c7 c0 c0 96 de 8b <48> 83 d9 00 48 85 c9 0f 84 72 01 00 00 48 81 f9 00 00 00 81 0f 82
RSP: 0000:ffffc90013a9f7e8 EFLAGS: 00000097
RAX: 0000000000000000 RBX: 1ffff92002753f05 RCX: ffffffff81b5bdeb
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000001 R08: ffffffff8bde96c0 R09: ffffffff8e3f15fe
R10: 0000000000084083 R11: 0000000000000001 R12: ffffc90013a9f908
R13: ffffc90013a9f8f5 R14: ffffc90013a9f910 R15: ffffc90013a9f8c0
FS:  0000000000000000(0000) GS:ffff8880b9d00000(0063) knlGS:00000000f55e9b40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000000000050 CR3: 000000002c476000 CR4: 00000000001526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 arch_stack_walk+0x7d/0xe0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:121
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:356
 ____kasan_slab_free+0xe1/0x110 mm/kasan/common.c:362
 kasan_slab_free include/linux/kasan.h:192 [inline]
 slab_free_hook mm/slub.c:1547 [inline]
 slab_free_freelist_hook+0x51/0x130 mm/slub.c:1580
 slab_free mm/slub.c:3143 [inline]
 kmem_cache_free+0x82/0x350 mm/slub.c:3159
 __sigqueue_free kernel/signal.c:454 [inline]
 dequeue_synchronous_signal kernel/signal.c:745 [inline]
 get_signal+0xb77/0x20f0 kernel/signal.c:2661
 arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:811
 handle_signal_work kernel/entry/common.c:147 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x148/0x250 kernel/entry/common.c:201
 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:307
 exc_page_fault+0xc6/0x180 arch/x86/mm/fault.c:1528
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:580
RIP: 0023:0x8052087
Code: 0c 50 e8 2c 5a 01 00 83 c4 10 85 c0 0f 84 b9 01 00 00 65 f0 83 2d d8 ff ff ff 01 8b 5c 24 08 e8 ef f6 00 00 8b 4c 24 0c 8b 00 <8b> 71 50 89 41 54 85 c0 75 05 83 fe ff 74 19 6b 44 24 1c 34 8b 4c
RSP: 002b:00000000f55e9640 EFLAGS: 00010283
RAX: 000000000000000e RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000008052064 RSI: 0000000000000005 RDI: 00000000080e76cb
RBP: 000000000818afc0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000