INFO: task krfcommd:4782 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:29296 pid: 4782 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-executor580:8511 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-executor580 state:D stack:27528 pid: 8511 ppid: 8479 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:1311 __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:00007fff9fc63fe8 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: 00000000013dc2b8 R13: 0000000000000072 R14: 00007fff9fc64040 R15: 0000000000000003 Showing all locks held in the system: 1 lock held by khungtaskd/1656: #0: ffffffff8b97c280 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6446 1 lock held by krfcommd/4782: #0: ffffffff8d3051e8 (rfcomm_mutex){+.+.}-{3:3}, at: rfcomm_process_sessions net/bluetooth/rfcomm/core.c:1979 [inline] #0: ffffffff8d3051e8 (rfcomm_mutex){+.+.}-{3:3}, at: rfcomm_run+0x2ed/0x4a20 net/bluetooth/rfcomm/core.c:2086 1 lock held by in:imklog/8298: #0: ffff88802a63eaf0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:974 4 locks held by syz-executor580/8511: #0: ffff888038afcc90 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:774 [inline] #0: ffff888038afcc90 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: __sock_release+0x86/0x280 net/socket.c:648 #1: ffff888145aad120 (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1612 [inline] #1: ffff888145aad120 (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}-{0:0}, at: rfcomm_sock_shutdown+0x54/0x210 net/bluetooth/rfcomm/sock.c:928 #2: ffffffff8d3051e8 (rfcomm_mutex){+.+.}-{3:3}, at: rfcomm_dlc_close+0x34/0x240 net/bluetooth/rfcomm/core.c:507 #3: ffff888012048528 (&d->lock){+.+.}-{3:3}, at: __rfcomm_dlc_close+0x162/0x8a0 net/bluetooth/rfcomm/core.c:487 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1656 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 8299 Comm: rs:main Q:Reg Not tainted 5.14.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:write_comp_data kernel/kcov.c:218 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x15/0x80 kernel/kcov.c:270 Code: 00 48 89 4c 38 f0 4e 89 54 c8 20 48 89 10 c3 66 0f 1f 44 00 00 53 41 89 fb 41 89 f1 bf 03 00 00 00 65 48 8b 0c 25 40 f0 01 00 <48> 89 ce 4c 8b 54 24 08 e8 4e f1 ff ff 84 c0 74 51 48 8b 81 18 15 RSP: 0018:ffffc9000caa7528 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffc9000caa75f0 RCX: ffff88801e8354c0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 0000000000000034 R08: 0000000000001000 R09: 0000000000000000 R10: ffffffff83f4bed0 R11: 000000000000003f R12: ffff88801f62e3c0 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007fc28c8ed700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc111180000 CR3: 0000000033dd6000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: get_offset lib/xarray.c:144 [inline] xas_descend+0x71/0x3b0 lib/xarray.c:203 xas_load+0xe5/0x140 lib/xarray.c:240 xa_get_order+0xf7/0x390 lib/xarray.c:1761 __add_to_page_cache_locked+0x4e7/0x1040 mm/filemap.c:884 add_to_page_cache_lru+0x173/0x5c0 mm/filemap.c:967 pagecache_get_page+0x46d/0x18d0 mm/filemap.c:1896 grab_cache_page_write_begin+0x64/0x90 mm/filemap.c:3610 ext4_da_write_begin+0x354/0x11c0 fs/ext4/inode.c:2984 generic_perform_write+0x202/0x500 mm/filemap.c:3656 ext4_buffered_write_iter+0x244/0x4d0 fs/ext4/file.c:269 ext4_file_write_iter+0x423/0x14e0 fs/ext4/file.c:680 call_write_iter include/linux/fs.h:2114 [inline] new_sync_write+0x426/0x650 fs/read_write.c:518 vfs_write+0x75a/0xa40 fs/read_write.c:605 ksys_write+0x12d/0x250 fs/read_write.c:658 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: 0033:0x7fc28f3311cd Code: c2 20 00 00 75 10 b8 01 00 00 00 0f 05 48 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 ae fc ff ff 48 89 04 24 b8 01 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 f7 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007fc28c8ec590 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fc284022ef0 RCX: 00007fc28f3311cd RDX: 00000000000004c9 RSI: 00007fc284022ef0 RDI: 0000000000000006 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 00007fc284022c70 R13: 00007fc28c8ec5b0 R14: 0000559bb129e360 R15: 00000000000004c9 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.097 msecs ---------------- Code disassembly (best guess): 0: 00 48 89 add %cl,-0x77(%rax) 3: 4c 38 f0 rex.WR cmp %r14b,%al 6: 4e 89 54 c8 20 mov %r10,0x20(%rax,%r9,8) b: 48 89 10 mov %rdx,(%rax) e: c3 retq f: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) 15: 53 push %rbx 16: 41 89 fb mov %edi,%r11d 19: 41 89 f1 mov %esi,%r9d 1c: bf 03 00 00 00 mov $0x3,%edi 21: 65 48 8b 0c 25 40 f0 mov %gs:0x1f040,%rcx 28: 01 00 * 2a: 48 89 ce mov %rcx,%rsi <-- trapping instruction 2d: 4c 8b 54 24 08 mov 0x8(%rsp),%r10 32: e8 4e f1 ff ff callq 0xfffff185 37: 84 c0 test %al,%al 39: 74 51 je 0x8c 3b: 48 rex.W 3c: 8b .byte 0x8b 3d: 81 .byte 0x81 3e: 18 .byte 0x18 3f: 15 .byte 0x15