INFO: task syz-executor.4:17531 blocked for more than 140 seconds. Not tainted 4.19.211-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D29752 17531 8174 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x887/0x2040 kernel/sched/core.c:3517 schedule+0x8d/0x1b0 kernel/sched/core.c:3561 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline] rwsem_down_read_failed+0x20a/0x390 kernel/locking/rwsem-xadd.c:309 call_rwsem_down_read_failed+0x14/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] down_read+0x44/0x80 kernel/locking/rwsem.c:26 iterate_supers+0xdb/0x290 fs/super.c:631 ksys_sync+0x86/0x150 fs/sync.c:113 __ia32_sys_sync+0xa/0x10 fs/sync.c:124 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f993b6590c9 Code: Bad RIP value. RSP: 002b:00007f9939bcb168 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f993b778f80 RCX: 00007f993b6590c9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f993b6b4ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd6ab6271f R14: 00007f9939bcb300 R15: 0000000000022000 Showing all locks held in the system: 2 locks held by kworker/u4:2/125: 1 lock held by khungtaskd/1570: #0: 00000000dbfb7626 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441 1 lock held by systemd-udevd/4701: 1 lock held by in:imklog/7799: 4 locks held by rs:main Q:Reg/7800: 3 locks held by kworker/u4:5/8742: 3 locks held by kworker/0:4/9341: 1 lock held by syz-executor.3/14763: 1 lock held by syz-executor.4/17531: #0: 00000000c142b309 (&type->s_umount_key#53){++++}, at: iterate_supers+0xdb/0x290 fs/super.c:631 1 lock held by syz-executor.1/17582: #0: 00000000c142b309 (&type->s_umount_key#53){++++}, at: iterate_supers+0xdb/0x290 fs/super.c:631 2 locks held by syz-executor.1/19729: 2 locks held by syz-executor.1/19732: #0: 0000000026d97fef (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 00000000f870b5fa (&tty->atomic_write_lock){+.+.}, at: tty_write_lock drivers/tty/tty_io.c:886 [inline] #1: 00000000f870b5fa (&tty->atomic_write_lock){+.+.}, at: do_tty_write drivers/tty/tty_io.c:909 [inline] #1: 00000000f870b5fa (&tty->atomic_write_lock){+.+.}, at: tty_write+0x24e/0x810 drivers/tty/tty_io.c:1044 1 lock held by syz-executor.5/19736: 2 locks held by syz-executor.4/19719: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1570 Comm: khungtaskd Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 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+0x33f/0x460 kernel/kthread.c:259 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: 19729 Comm: syz-executor.1 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023 RIP: 0010:arch_local_irq_disable arch/x86/include/asm/paravirt.h:794 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/paravirt.h:807 [inline] RIP: 0010:lock_is_held_type+0xb8/0x210 kernel/locking/lockdep.c:3942 Code: fc ff df 48 89 c3 48 c7 c0 90 82 f1 89 48 c1 e8 03 80 3c 10 00 0f 85 4c 01 00 00 48 83 3d 0f cd a6 08 00 0f 84 e8 00 00 00 fa <66> 0f 1f 44 00 00 65 4c 8b 24 25 c0 df 01 00 49 8d bc 24 84 08 00 RSP: 0018:ffff888048e5f6f0 EFLAGS: 00000082 RAX: 1ffffffff13e3052 RBX: 0000000000000286 RCX: 0000000000000001 RDX: dffffc0000000000 RSI: 00000000ffffffff RDI: ffff8880b383adc4 RBP: ffffffff89f85f20 R08: ffffffff8700475a R09: 0000000000000000 R10: 0000000000000005 R11: 0000000000000000 R12: 0000000000000398 R13: ffff88804673e4e8 R14: ffff888048e5f918 R15: ffffffff8700475a FS: 00007f248e6ac700(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020200030 CR3: 00000000a8e25000 CR4: 00000000003406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_is_held include/linux/lockdep.h:344 [inline] ___might_sleep+0x227/0x2b0 kernel/sched/core.c:6157 __mutex_lock_common kernel/locking/mutex.c:920 [inline] __mutex_lock+0xab/0x1190 kernel/locking/mutex.c:1078 unix_dgram_recvmsg+0x23a/0xdb0 net/unix/af_unix.c:2142 ___sys_recvmsg+0x255/0x570 net/socket.c:2389 __sys_recvmmsg+0x254/0x6d0 net/socket.c:2501 do_sys_recvmmsg+0x172/0x190 net/socket.c:2577 __do_sys_recvmmsg net/socket.c:2595 [inline] __se_sys_recvmmsg net/socket.c:2591 [inline] __x64_sys_recvmmsg+0xba/0x150 net/socket.c:2591 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f249015b0c9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f248e6ac168 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f249027b050 RCX: 00007f249015b0c9 RDX: 0000000000010106 RSI: 00000000200000c0 RDI: 0000000000000007 RBP: 00007f24901b6ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffdd6f5178f R14: 00007f248e6ac300 R15: 0000000000022000