syzbot


INFO: task hung in rfcomm_process_sessions

Status: auto-closed as invalid on 2021/12/18 18:49
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 435d, last: 435d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in rfcomm_process_sessions (2) C error error 14 93d 244d 0/24 upstream: reported C repro on 2022/03/30 01:34

Sample crash report:
INFO: task krfcommd:2875 blocked for more than 143 seconds.
      Not tainted 5.15.0-rc1-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:krfcommd        state:D stack:28296 pid: 2875 ppid:     2 flags:0x00004000
Call Trace:
 context_switch kernel/sched/core.c:4940 [inline]
 __schedule+0xc8d/0x1270 kernel/sched/core.c:6287
 schedule+0x14b/0x210 kernel/sched/core.c:6366
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6425
 __mutex_lock_common+0xdff/0x2550 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:743
 rfcomm_process_sessions+0x21/0x3f0 net/bluetooth/rfcomm/core.c:1979
 rfcomm_run+0x195/0x2c0 net/bluetooth/rfcomm/core.c:2086
 kthread+0x453/0x480 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30
INFO: task syz-executor.5:30772 blocked for more than 143 seconds.
      Not tainted 5.15.0-rc1-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.5  state:D stack:25496 pid:30772 ppid: 27366 flags:0x00004006
Call Trace:
 context_switch kernel/sched/core.c:4940 [inline]
 __schedule+0xc8d/0x1270 kernel/sched/core.c:6287
 schedule+0x14b/0x210 kernel/sched/core.c:6366
 __lock_sock+0x1cf/0x330 net/core/sock.c:2644
 lock_sock_nested+0x7b/0x110 net/core/sock.c:3185
 lock_sock include/net/sock.h:1612 [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:931
 rfcomm_sock_release+0x55/0x120 net/bluetooth/rfcomm/sock.c:951
 __sock_release net/socket.c:649 [inline]
 sock_close+0xd8/0x260 net/socket.c:1314
 __fput+0x3fe/0x870 fs/file_table.c:280
 task_work_run+0x146/0x1c0 kernel/task_work.c:164
 get_signal+0x2014/0x20c0 kernel/signal.c:2641
 arch_do_signal_or_restart+0x9c/0x730 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+0x191/0x220 kernel/entry/common.c:209
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x2e/0x70 kernel/entry/common.c:302
 do_syscall_64+0x53/0xd0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f8f6481b739
RSP: 002b:00007f8f61d92188 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: fffffffffffffffc RBX: 00007f8f6491ff80 RCX: 00007f8f6481b739
RDX: 0000000000000080 RSI: 0000000020000000 RDI: 0000000000000005
RBP: 00007f8f64875cc4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f8f6491ff80
R13: 00007fffb89ecf1f R14: 00007f8f61d92300 R15: 0000000000022000

Showing all locks held in the system:
1 lock held by khungtaskd/26:
 #0: ffffffff8c91c180 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
1 lock held by krfcommd/2875:
 #0: ffffffff8dac67c8 (rfcomm_mutex){+.+.}-{3:3}, at: rfcomm_process_sessions+0x21/0x3f0 net/bluetooth/rfcomm/core.c:1979
1 lock held by in:imklog/6203:
 #0: ffff888023e8d9f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x24e/0x2f0 fs/file.c:990
4 locks held by kworker/u4:7/9399:
3 locks held by kworker/0:1/23110:
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7ca/0x1140
 #1: ffffc9000448fd20 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x808/0x1140 kernel/workqueue.c:2272
 #2: ffffffff8d95b448 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:74
3 locks held by kworker/0:6/26608:
 #0: ffff888011064d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7ca/0x1140
 #1: ffffc90002dbfd20 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x808/0x1140 kernel/workqueue.c:2272
 #2: ffffffff8d95b448 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:251
4 locks held by syz-executor.5/30772:
 #0: ffff888039876e10 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:786 [inline]
 #0: ffff888039876e10 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: __sock_release net/socket.c:648 [inline]
 #0: ffff888039876e10 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: sock_close+0x94/0x260 net/socket.c:1314
 #1: ffff8880801ba120 (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1612 [inline]
 #1: ffff8880801ba120 (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}-{0:0}, at: rfcomm_sock_shutdown+0x51/0x220 net/bluetooth/rfcomm/sock.c:928
 #2: ffffffff8dac67c8 (rfcomm_mutex){+.+.}-{3:3}, at: rfcomm_dlc_close+0x32/0x1c0 net/bluetooth/rfcomm/core.c:507
 #3: ffff88803b0a2128 (&d->lock){+.+.}-{3:3}, at: __rfcomm_dlc_close+0x281/0x480 net/bluetooth/rfcomm/core.c:487

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

NMI backtrace for cpu 0
CPU: 0 PID: 26 Comm: khungtaskd Not tainted 5.15.0-rc1-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+0x1dc/0x2d8 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x45f/0x490 lib/nmi_backtrace.c:105
 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:210 [inline]
 watchdog+0xc54/0xca0 kernel/hung_task.c:295
 kthread+0x453/0x480 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 29856 Comm: kworker/1:11 Not tainted 5.15.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_power_efficient wg_ratelimiter_gc_entries
RIP: 0010:kasan_check_range+0x224/0x2f0 mm/kasan/generic.c:189
Code: 89 cf 49 8d 5e 07 4d 85 f6 49 0f 49 de 48 83 e3 f8 49 29 de 74 11 45 0f b6 1f 45 84 db 75 64 49 ff c7 49 ff ce 75 ef 5b 41 5c <41> 5d 41 5e 41 5f c3 45 84 db 75 50 45 8a 59 01 45 84 db 0f 85 8a
RSP: 0018:ffffc900033cf6e0 EFLAGS: 00000056
RAX: 0000000000000001 RBX: 00000000000006e6 RCX: ffffffff81648361
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8fd17ed8
RBP: ffffc900033cf8f0 R08: dffffc0000000000 R09: fffffbfff1fa2fdc
R10: fffffbfff1fa2fdc R11: 0000000000000000 R12: 1ffff92000679eec
R13: dffffc0000000001 R14: 0000000000000001 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c021e1a4e0 CR3: 000000000c68e000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 instrument_atomic_read include/linux/instrumented.h:71 [inline]
 test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline]
 hlock_class kernel/locking/lockdep.c:199 [inline]
 mark_lock+0x191/0x1e00 kernel/locking/lockdep.c:4571
 mark_usage kernel/locking/lockdep.c:4502 [inline]
 __lock_acquire+0xccf/0x2b00 kernel/locking/lockdep.c:4969
 lock_acquire+0x19f/0x4d0 kernel/locking/lockdep.c:5625
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:363 [inline]
 wg_ratelimiter_gc_entries+0x5c/0x4a0 drivers/net/wireguard/ratelimiter.c:63
 process_one_work+0x853/0x1140 kernel/workqueue.c:2297
 worker_thread+0xac1/0x1320 kernel/workqueue.c:2444
 kthread+0x453/0x480 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30
----------------
Code disassembly (best guess):
   0:	89 cf                	mov    %ecx,%edi
   2:	49 8d 5e 07          	lea    0x7(%r14),%rbx
   6:	4d 85 f6             	test   %r14,%r14
   9:	49 0f 49 de          	cmovns %r14,%rbx
   d:	48 83 e3 f8          	and    $0xfffffffffffffff8,%rbx
  11:	49 29 de             	sub    %rbx,%r14
  14:	74 11                	je     0x27
  16:	45 0f b6 1f          	movzbl (%r15),%r11d
  1a:	45 84 db             	test   %r11b,%r11b
  1d:	75 64                	jne    0x83
  1f:	49 ff c7             	inc    %r15
  22:	49 ff ce             	dec    %r14
  25:	75 ef                	jne    0x16
  27:	5b                   	pop    %rbx
  28:	41 5c                	pop    %r12
* 2a:	41 5d                	pop    %r13 <-- trapping instruction
  2c:	41 5e                	pop    %r14
  2e:	41 5f                	pop    %r15
  30:	c3                   	retq
  31:	45 84 db             	test   %r11b,%r11b
  34:	75 50                	jne    0x86
  36:	45 8a 59 01          	mov    0x1(%r9),%r11b
  3a:	45 84 db             	test   %r11b,%r11b
  3d:	0f                   	.byte 0xf
  3e:	85                   	.byte 0x85
  3f:	8a                   	.byte 0x8a

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-smack-root 2021/09/19 18:44 upstream d4d016caa4b8 70b76c1d .config log report info INFO: task hung in rfcomm_process_sessions
* Struck through repros no longer work on HEAD.