INFO: task krfcommd:4784 blocked for more than 143 seconds. Not tainted 5.14.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:krfcommd state:D stack:29136 pid: 4784 ppid: 2 flags:0x00004000 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 rfcomm_process_sessions net/bluetooth/rfcomm/core.c:1979 [inline] rfcomm_run+0x2ed/0x4a20 net/bluetooth/rfcomm/core.c:2086 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 INFO: task syz-executor828:8495 blocked for more than 143 seconds. Not tainted 5.14.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor828 state:D stack:27528 pid: 8495 ppid: 8463 flags:0x00004006 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 __lock_sock+0x13d/0x260 net/core/sock.c:2644 lock_sock_nested+0xf6/0x120 net/core/sock.c:3185 lock_sock include/net/sock.h:1612 [inline] rfcomm_sk_state_change+0xb4/0x390 net/bluetooth/rfcomm/sock.c:73 __rfcomm_dlc_close+0x1b6/0x8a0 net/bluetooth/rfcomm/core.c:489 rfcomm_dlc_close+0x1ea/0x240 net/bluetooth/rfcomm/core.c:520 __rfcomm_sock_close+0xac/0x260 net/bluetooth/rfcomm/sock.c:220 rfcomm_sock_shutdown+0xe9/0x210 net/bluetooth/rfcomm/sock.c:931 rfcomm_sock_release+0x5f/0x140 net/bluetooth/rfcomm/sock.c:951 __sock_release+0xcd/0x280 net/socket.c:649 sock_close+0x18/0x20 net/socket.c:1314 __fput+0x288/0x920 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 exit_task_work include/linux/task_work.h:32 [inline] do_exit+0xbd4/0x2a60 kernel/exit.c:825 do_group_exit+0x125/0x310 kernel/exit.c:922 get_signal+0x47f/0x2160 kernel/signal.c:2808 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:865 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x445fe9 RSP: 002b:00007fff787fd7a8 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: fffffffffffffffc RBX: 0000000000000003 RCX: 0000000000445fe9 RDX: 0000000000000080 RSI: 0000000020000000 RDI: 0000000000000004 RBP: 0000000000000003 R08: 000000ff00000001 R09: 000000ff00000001 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000013b82b8 R13: 0000000000000072 R14: 00007fff787fd800 R15: 0000000000000003 Showing all locks held in the system: 1 lock held by khungtaskd/1636: #0: ffffffff8b97c280 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6446 1 lock held by krfcommd/4784: #0: ffffffff8d306528 (rfcomm_mutex){+.+.}-{3:3}, at: rfcomm_process_sessions net/bluetooth/rfcomm/core.c:1979 [inline] #0: ffffffff8d306528 (rfcomm_mutex){+.+.}-{3:3}, at: rfcomm_run+0x2ed/0x4a20 net/bluetooth/rfcomm/core.c:2086 1 lock held by in:imklog/8166: #0: ffff888033222370 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:974 4 locks held by syz-executor828/8495: #0: ffff888031c21710 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:774 [inline] #0: ffff888031c21710 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: __sock_release+0x86/0x280 net/socket.c:648 #1: ffff88801e8fc120 (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1612 [inline] #1: ffff88801e8fc120 (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}-{0:0}, at: rfcomm_sock_shutdown+0x54/0x210 net/bluetooth/rfcomm/sock.c:928 #2: ffffffff8d306528 (rfcomm_mutex){+.+.}-{3:3}, at: rfcomm_dlc_close+0x34/0x240 net/bluetooth/rfcomm/core.c:507 #3: ffff888029ebc128 (&d->lock){+.+.}-{3:3}, at: __rfcomm_dlc_close+0x162/0x8a0 net/bluetooth/rfcomm/core.c:487 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1636 Comm: khungtaskd Not tainted 5.14.0-rc7-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: 4874 Comm: systemd-journal Not tainted 5.14.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_acquire+0x7d/0x54a0 kernel/locking/lockdep.c:4873 Code: 24 20 48 8d 84 24 88 00 00 00 48 c1 e8 03 48 89 44 24 30 48 89 c6 48 b8 00 00 00 00 00 fc ff df 48 8d 14 06 c7 02 f1 f1 f1 f1 42 04 00 f3 f3 f3 48 c7 c2 6c 0d 6d 8d 65 48 8b 34 25 28 00 00 RSP: 0018:ffffc9000156f848 EFLAGS: 00000802 RAX: dffffc0000000000 RBX: ffff8880b9d51a58 RCX: 0000000000000000 RDX: fffff520002adf1a RSI: 1ffff920002adf1a RDI: ffff8880b9d51a58 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001 FS: 00007fb3aba878c0(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb3a8e5c000 CR3: 000000001caa7000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 _raw_spin_lock_nested+0x30/0x40 kernel/locking/spinlock.c:361 raw_spin_rq_lock_nested kernel/sched/core.c:460 [inline] raw_spin_rq_lock kernel/sched/sched.h:1307 [inline] rq_lock kernel/sched/sched.h:1610 [inline] __schedule+0x233/0x26f0 kernel/sched/core.c:5852 schedule+0xd3/0x270 kernel/sched/core.c:6017 schedule_hrtimeout_range_clock+0x343/0x390 kernel/time/hrtimer.c:2148 ep_poll fs/eventpoll.c:1848 [inline] do_epoll_wait+0x1283/0x1950 fs/eventpoll.c:2226 __do_sys_epoll_wait fs/eventpoll.c:2238 [inline] __se_sys_epoll_wait fs/eventpoll.c:2233 [inline] __x64_sys_epoll_wait+0x158/0x270 fs/eventpoll.c:2233 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: 0033:0x7fb3aad502e3 Code: 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 83 3d 29 54 2b 00 00 75 13 49 89 ca b8 e8 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 34 c3 48 83 ec 08 e8 0b c2 00 00 48 89 04 24 RSP: 002b:00007ffdcb6261f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e8 RAX: ffffffffffffffda RBX: 000055b66fd171e0 RCX: 00007fb3aad502e3 RDX: 0000000000000013 RSI: 00007ffdcb626200 RDI: 0000000000000008 RBP: 00007ffdcb6263f0 R08: 00000000612fb27e R09: 00007ffdcb63c080 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffdcb626200 R13: 0000000000000001 R14: ffffffffffffffff R15: 0005caf20d54546d ---------------- Code disassembly (best guess): 0: 24 20 and $0x20,%al 2: 48 8d 84 24 88 00 00 lea 0x88(%rsp),%rax 9: 00 a: 48 c1 e8 03 shr $0x3,%rax e: 48 89 44 24 30 mov %rax,0x30(%rsp) 13: 48 89 c6 mov %rax,%rsi 16: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 1d: fc ff df 20: 48 8d 14 06 lea (%rsi,%rax,1),%rdx 24: c7 02 f1 f1 f1 f1 movl $0xf1f1f1f1,(%rdx) * 2a: c7 42 04 00 f3 f3 f3 movl $0xf3f3f300,0x4(%rdx) <-- trapping instruction 31: 48 c7 c2 6c 0d 6d 8d mov $0xffffffff8d6d0d6c,%rdx 38: 65 gs 39: 48 rex.W 3a: 8b .byte 0x8b 3b: 34 25 xor $0x25,%al 3d: 28 00 sub %al,(%rax)