INFO: rcu detected stall in n_tty_receive_buf_common

Status: closed as dup on 2018/03/31 15:56
Subsystems: serial
[Documentation on labels]
Reported-by: syzbot+b7d0f37ffd431e2d698c@syzkaller.appspotmail.com
First crash: 3040d, last: 2954d
▶ ▼ Duplicate of
Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported
INFO: rcu detected stall in __process_echoes serial 1 C 326 2946d 3042d
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
INFO: rcu detected stall in n_tty_receive_buf_common 1 (2) 2018/03/31 15:56

Sample crash report:
INFO: rcu_sched self-detected stall on CPU
	1-....: (124999 ticks this GP) idle=55a/1/4611686018427387906 softirq=11550/11550 fqs=31230 
	 (t=125000 jiffies g=5748 c=5747 q=7)
NMI backtrace for cpu 1
CPU: 1 PID: 40 Comm: kworker/u4:2 Not tainted 4.17.0-rc3+ #32
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_unbound flush_to_ldisc
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold.4+0x19/0xce lib/nmi_backtrace.c:103
 nmi_trigger_cpumask_backtrace+0x151/0x192 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_single_cpu_backtrace include/linux/nmi.h:156 [inline]
 rcu_dump_cpu_stacks+0x175/0x1c2 kernel/rcu/tree.c:1376
 print_cpu_stall kernel/rcu/tree.c:1525 [inline]
 check_cpu_stall.isra.61.cold.80+0x36c/0x59a kernel/rcu/tree.c:1593
 __rcu_pending kernel/rcu/tree.c:3356 [inline]
 rcu_pending kernel/rcu/tree.c:3401 [inline]
 rcu_check_callbacks+0x21b/0xad0 kernel/rcu/tree.c:2763
 update_process_times+0x2d/0x70 kernel/time/timer.c:1636
 tick_sched_handle+0x9f/0x180 kernel/time/tick-sched.c:164
 tick_sched_timer+0x45/0x130 kernel/time/tick-sched.c:1274
 __run_hrtimer kernel/time/hrtimer.c:1398 [inline]
 __hrtimer_run_queues+0x3e3/0x10a0 kernel/time/hrtimer.c:1460
 hrtimer_interrupt+0x2f3/0x750 kernel/time/hrtimer.c:1518
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline]
 smp_apic_timer_interrupt+0x15d/0x710 arch/x86/kernel/apic/apic.c:1050
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863
 </IRQ>
RIP: 0010:__process_echoes+0x272/0x8d0 drivers/tty/n_tty.c:731
RSP: 0018:ffff8801d958f2a8 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13
RAX: ffff8801d9580280 RBX: 00000002c88f0eea RCX: ffffffff8397bdf9
RDX: 0000000000000000 RSI: fffffffd37711a37 RDI: 0000000000000edf
RBP: ffff8801d958f310 R08: ffff8801d9580280 R09: 0000000000000006
R10: ffff8801d9580280 R11: 0000000000000000 R12: ffffc90002e4a000
R13: 0000000000002921 R14: fffffffd37711a37 R15: 00000000000000ff
 flush_echoes drivers/tty/n_tty.c:799 [inline]
 __receive_buf drivers/tty/n_tty.c:1615 [inline]
 n_tty_receive_buf_common+0x11d5/0x2c50 drivers/tty/n_tty.c:1709
 n_tty_receive_buf2+0x33/0x40 drivers/tty/n_tty.c:1744
 tty_ldisc_receive_buf+0xb0/0x190 drivers/tty/tty_buffer.c:456
 tty_port_default_receive_buf+0x110/0x170 drivers/tty/tty_port.c:38
 receive_buf drivers/tty/tty_buffer.c:475 [inline]
 flush_to_ldisc+0x3e9/0x560 drivers/tty/tty_buffer.c:524
 process_one_work+0xc1e/0x1b50 kernel/workqueue.c:2145
 worker_thread+0x1cc/0x1440 kernel/workqueue.c:2279
 kthread+0x345/0x410 kernel/kthread.c:238
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412

Crashes (32):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/05/04 16:05 upstream 150426981426 9ce14f4b .config console log report syz C ci-upstream-kasan-gce-root
2018/03/29 15:56 upstream 0b412605ef5f d47f0ed6 .config console log report syz C ci-upstream-kasan-gce-root
2018/06/23 23:19 upstream 5e2204832b20 2064fc5c .config console log report ci-upstream-kasan-gce-root
2018/06/15 20:48 upstream 4c5e8fc62d6a 27c5f59f .config console log report ci-upstream-kasan-gce-root
2018/05/29 20:26 upstream 3d661e2a2d1c e276de77 .config console log report ci-upstream-kasan-gce-root
2018/05/28 20:57 upstream 786b71f5b754 f48c20b8 .config console log report ci-upstream-kasan-gce-root
2018/05/19 20:10 upstream 73fcb1a370c7 849705db .config console log report ci-upstream-kasan-gce-root
2018/05/17 23:44 upstream 305bb5521282 738d58ad .config console log report ci-upstream-kasan-gce-root
2018/05/15 13:54 upstream 67b8d5c70812 661fd7b9 .config console log report ci-upstream-kasan-gce-root
2018/05/12 20:37 upstream f0ab773f5c96 e726f42b .config console log report ci-upstream-kasan-gce-root
2018/05/12 20:32 upstream f0ab773f5c96 e726f42b .config console log report ci-upstream-kasan-gce-root
2018/05/12 16:53 upstream f0ab773f5c96 e726f42b .config console log report ci-upstream-kasan-gce-root
2018/05/11 07:09 upstream 008464a9360e 12c7428a .config console log report ci-upstream-kasan-gce-root
2018/05/10 21:01 upstream 008464a9360e 12c7428a .config console log report ci-upstream-kasan-gce-root
2018/05/10 12:22 upstream 008464a9360e 12c7428a .config console log report ci-upstream-kasan-gce-root
2018/05/05 21:46 upstream c1c07416cdd4 6a0382b5 .config console log report ci-upstream-kasan-gce-root
2018/05/05 06:38 upstream 625e2001e99e 9ce14f4b .config console log report ci-upstream-kasan-gce-root
2018/05/02 10:07 upstream f2125992e7cb d5b114b4 .config console log report ci-upstream-kasan-gce-root
2018/04/29 08:57 upstream cdface520934 d5a5d045 .config console log report ci-upstream-kasan-gce-root
2018/04/21 04:15 upstream 83beed7b2b26 ca03d688 .config console log report ci-upstream-kasan-gce-root
2018/04/20 19:10 upstream 43f70c960180 cc402841 .config console log report ci-upstream-kasan-gce-root
2018/04/20 12:02 upstream 87ef12027b9b eae05cb0 .config console log report ci-upstream-kasan-gce-root
2018/04/20 09:23 upstream 87ef12027b9b eae05cb0 .config console log report ci-upstream-kasan-gce-root
2018/04/19 09:13 upstream 87ef12027b9b d1b2ef69 .config console log report ci-upstream-kasan-gce-root
2018/04/17 07:39 upstream a27fc14219f2 b80fd3b5 .config console log report ci-upstream-kasan-gce-root
2018/04/16 21:07 upstream 60cc43fc8884 802ac912 .config console log report ci-upstream-kasan-gce-root
2018/04/16 07:34 upstream 71b8ebbf3d7b 7a67784c .config console log report ci-upstream-kasan-gce-root
2018/04/10 10:53 upstream c18bb396d3d2 b9f65507 .config console log report ci-upstream-kasan-gce-root
2018/04/09 23:25 upstream fd40ffc72e2f b9f65507 .config console log report ci-upstream-kasan-gce-root
2018/04/05 08:47 upstream 3e968c9f1401 676bd07e .config console log report ci-upstream-kasan-gce-root
2018/04/03 10:02 upstream 642e7fd23353 676bd07e .config console log report ci-upstream-kasan-gce-root
2018/03/31 03:28 upstream 9dd2326890d8 8fbce0e4 .config console log report ci-upstream-kasan-gce-root
* Struck through repros no longer work on HEAD.