syzbot


INFO: task hung in rfcomm_process_sessions (2)

Status: upstream: reported C repro on 2022/03/30 01:34
Reported-by: syzbot+d761775dff24be3ad4be@syzkaller.appspotmail.com
First crash: 191d, last: 36d

Cause bisection: failed (bisect log)
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in rfcomm_process_sessions 1 379d 379d 0/24 auto-closed as invalid on 2021/12/18 18:49
Patch testing requests:
Created Duration User Patch Repo Result
2022/03/30 10:26 9m hdanton@sina.com patch https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ cffb2b72d3ed OK

Sample crash report:
INFO: task krfcommd:2708 blocked for more than 143 seconds.
      Tainted: G        W         5.17.0-syzkaller-13034-gd888c83fcec7 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:krfcommd        state:D stack:29176 pid: 2708 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5073 [inline]
 __schedule+0x937/0x1090 kernel/sched/core.c:6382
 schedule+0xeb/0x1b0 kernel/sched/core.c:6454
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6513
 __mutex_lock_common+0xd1f/0x2590 kernel/locking/mutex.c:673
 __mutex_lock kernel/locking/mutex.c:733 [inline]
 mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:785
 rfcomm_process_sessions+0x21/0x3f0 net/bluetooth/rfcomm/core.c:2015
 rfcomm_run+0x195/0x2c0 net/bluetooth/rfcomm/core.c:2122
 kthread+0x2a3/0x2d0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30
 </TASK>
INFO: task syz-executor365:3631 blocked for more than 143 seconds.
      Tainted: G        W         5.17.0-syzkaller-13034-gd888c83fcec7 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor365 state:D stack:26552 pid: 3631 ppid:  3625 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5073 [inline]
 __schedule+0x937/0x1090 kernel/sched/core.c:6382
 schedule+0xeb/0x1b0 kernel/sched/core.c:6454
 __lock_sock+0x1cf/0x330 net/core/sock.c:2770
 lock_sock_nested+0x9f/0x100 net/core/sock.c:3317
 lock_sock include/net/sock.h:1682 [inline]
 rfcomm_sk_state_change+0x63/0x300 net/bluetooth/rfcomm/sock.c:73
 __rfcomm_dlc_close+0x2cc/0x480 net/bluetooth/rfcomm/core.c:489
 rfcomm_dlc_close+0x10d/0x1c0 net/bluetooth/rfcomm/core.c:520
 __rfcomm_sock_close+0x101/0x220 net/bluetooth/rfcomm/sock.c:220
 rfcomm_sock_shutdown+0xa5/0x220 net/bluetooth/rfcomm/sock.c:905
 rfcomm_sock_release+0x55/0x120 net/bluetooth/rfcomm/sock.c:925
 __sock_release net/socket.c:650 [inline]
 sock_close+0xd8/0x260 net/socket.c:1318
 __fput+0x3f6/0x860 fs/file_table.c:317
 task_work_run+0x146/0x1c0 kernel/task_work.c:164
 exit_task_work include/linux/task_work.h:37 [inline]
 do_exit+0x5e3/0x20c0 kernel/exit.c:795
 do_group_exit+0x2af/0x2b0 kernel/exit.c:925
 get_signal+0x23bd/0x23c0 kernel/signal.c:2904
 arch_do_signal_or_restart+0x8e/0x740 arch/x86/kernel/signal.c:867
 exit_to_user_mode_loop kernel/entry/common.c:180 [inline]
 exit_to_user_mode_prepare+0x128/0x1f0 kernel/entry/common.c:215
 __syscall_exit_to_user_mode_work kernel/entry/common.c:297 [inline]
 syscall_exit_to_user_mode+0x2e/0x70 kernel/entry/common.c:308
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f5789bd01b9
RSP: 002b:00007fff20bc4178 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: fffffffffffffffc RBX: 0000000000000003 RCX: 00007f5789bd01b9
RDX: 000000000000005a RSI: 0000000020000000 RDI: 0000000000000004
RBP: 0000000000000003 R08: 000000ff00000001 R09: 000000ff00000001
R10: 0000000000000000 R11: 0000000000000246 R12: 0000555555b182b8
R13: 0000000000000072 R14: 00007fff20bc41d0 R15: 0000000000000003
 </TASK>
INFO: lockdep is turned off.
NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Tainted: G        W         5.17.0-syzkaller-13034-gd888c83fcec7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1dc/0x2d8 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x45f/0x490 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x16a/0x280 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
 watchdog+0xc82/0xcd0 kernel/hung_task.c:369
 kthread+0x2a3/0x2d0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 983 Comm: kworker/u4:4 Tainted: G        W         5.17.0-syzkaller-13034-gd888c83fcec7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:insn_get_prefixes+0xbef/0x1930 arch/x86/lib/insn.c:195
Code: 44 8a 6d 00 41 0f b6 fd e8 be 99 ff ff 41 89 c4 41 83 e4 0f 41 8d 5c 24 f3 bf 02 00 00 00 89 de e8 86 c5 28 fd 83 fb 03 72 0a <e8> 6c c1 28 fd e9 c5 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b
RSP: 0018:ffffc90004f7f638 EFLAGS: 00000286
RAX: 0000000000000000 RBX: 00000000fffffff3 RCX: dffffc0000000000
RDX: ffff88801d405700 RSI: 00000000fffffff3 RDI: 0000000000000002
RBP: ffffffff81d6dd5e R08: ffffffff845d45ca R09: ffffc90004f7f980
R10: fffff520009eff3b R11: 0000000000000000 R12: 0000000000000000
R13: ffffc90004f7f9e9 R14: ffffc90004f7f9e0 R15: 1ffff920009eff3a
FS:  0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005579209be000 CR3: 000000000ca8e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 insn_get_opcode+0x1c5/0xa90 arch/x86/lib/insn.c:272
 insn_get_modrm+0x205/0x760 arch/x86/lib/insn.c:343
 insn_get_sib arch/x86/lib/insn.c:421 [inline]
 insn_get_displacement+0x12a/0xa90 arch/x86/lib/insn.c:464
 insn_get_immediate+0x404/0x1fe0 arch/x86/lib/insn.c:632
 insn_get_length arch/x86/lib/insn.c:707 [inline]
 insn_decode+0x350/0x4c0 arch/x86/lib/insn.c:747
 arch_jump_entry_size arch/x86/kernel/jump_label.c:24 [inline]
 __jump_label_patch+0xdf/0x410 arch/x86/kernel/jump_label.c:45
 arch_jump_label_transform_queue+0x49/0xd0 arch/x86/kernel/jump_label.c:137
 __jump_label_update+0x15d/0x350 kernel/jump_label.c:451
 static_key_disable_cpuslocked+0xcc/0x1b0 kernel/jump_label.c:207
 static_key_disable+0x16/0x20 kernel/jump_label.c:215
 toggle_allocation_gate+0x3c8/0x460 mm/kfence/core.c:793
 process_one_work+0x83c/0x11a0 kernel/workqueue.c:2289
 worker_thread+0xa6c/0x1290 kernel/workqueue.c:2436
 kthread+0x2a3/0x2d0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30
 </TASK>
----------------
Code disassembly (best guess):
   0:	44 8a 6d 00          	mov    0x0(%rbp),%r13b
   4:	41 0f b6 fd          	movzbl %r13b,%edi
   8:	e8 be 99 ff ff       	callq  0xffff99cb
   d:	41 89 c4             	mov    %eax,%r12d
  10:	41 83 e4 0f          	and    $0xf,%r12d
  14:	41 8d 5c 24 f3       	lea    -0xd(%r12),%ebx
  19:	bf 02 00 00 00       	mov    $0x2,%edi
  1e:	89 de                	mov    %ebx,%esi
  20:	e8 86 c5 28 fd       	callq  0xfd28c5ab
  25:	83 fb 03             	cmp    $0x3,%ebx
  28:	72 0a                	jb     0x34
* 2a:	e8 6c c1 28 fd       	callq  0xfd28c19b <-- trapping instruction
  2f:	e9 c5 00 00 00       	jmpq   0xf9
  34:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  3b:	fc ff df
  3e:	48                   	rex.W
  3f:	8b                   	.byte 0x8b

Fix bisection attempts:
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-smack-root 2022/08/28 00:46 upstream 10d4879f9ef0 42718dd6 .config log report syz C
ci-upstream-kasan-gce-smack-root 2022/07/29 00:23 upstream 33ea1340bafe 42718dd6 .config log report syz C
ci-upstream-kasan-gce-smack-root 2022/06/29 00:00 upstream 941e3e791269 42718dd6 .config log report syz C
ci-upstream-kasan-gce-smack-root 2022/05/29 20:44 upstream b00ed48bb0a7 42718dd6 .config log report syz C
ci-upstream-kasan-gce-smack-root 2022/04/29 19:57 upstream 3e71713c9e75 42718dd6 .config log report syz C
* Struck through repros no longer work on HEAD.
Crashes (14):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-smack-root 2022/03/30 19:36 upstream d888c83fcec7 42718dd6 .config log report syz C INFO: task hung in rfcomm_process_sessions
ci-upstream-kasan-gce-smack-root 2022/03/29 13:29 upstream cffb2b72d3ed 6bdac766 .config log report syz C INFO: task hung in rfcomm_process_sessions
ci-upstream-kasan-gce-smack-root 2022/03/29 11:10 upstream cffb2b72d3ed 6bdac766 .config log report syz C INFO: task hung in rfcomm_process_sessions
ci-upstream-kasan-gce-smack-root 2022/03/28 23:09 upstream ae085d7f9365 ee339263 .config log report syz C INFO: task hung in rfcomm_process_sessions
ci-upstream-kasan-gce-smack-root 2022/03/27 20:34 upstream f022814633e1 89bc8608 .config log report syz C INFO: task hung in rfcomm_process_sessions
ci-upstream-kasan-gce-smack-root 2022/03/27 18:14 upstream f022814633e1 89bc8608 .config log report syz C INFO: task hung in rfcomm_process_sessions
ci-upstream-kasan-gce-smack-root 2022/03/27 09:37 upstream bddac7c1e02b 89bc8608 .config log report syz C INFO: task hung in rfcomm_process_sessions
ci-upstream-kasan-gce-smack-root 2022/03/27 08:03 upstream bddac7c1e02b 89bc8608 .config log report syz C INFO: task hung in rfcomm_process_sessions
ci-upstream-kasan-gce-smack-root 2022/03/27 03:29 upstream bddac7c1e02b 89bc8608 .config log report syz C INFO: task hung in rfcomm_process_sessions
ci-upstream-kasan-gce-smack-root 2022/03/26 20:18 upstream 52d543b5497c 89bc8608 .config log report syz C INFO: task hung in rfcomm_process_sessions
ci-upstream-kasan-gce-smack-root 2022/03/26 18:33 upstream 52d543b5497c 89bc8608 .config log report syz C INFO: task hung in rfcomm_process_sessions
ci-upstream-kasan-gce-smack-root 2022/03/26 14:59 upstream 52d543b5497c 89bc8608 .config log report syz C INFO: task hung in rfcomm_process_sessions
ci-upstream-kasan-gce-smack-root 2022/03/26 11:34 upstream 52d543b5497c 89bc8608 .config log report syz C INFO: task hung in rfcomm_process_sessions
ci-upstream-kasan-gce-smack-root 2022/03/26 01:30 upstream 34af78c4e616 89bc8608 .config log report syz C INFO: task hung in rfcomm_process_sessions
* Struck through repros no longer work on HEAD.