syzbot


INFO: task hung in vhost_init_device_iotlb

Status: closed as invalid on 2019/07/02 07:23
Subsystems: virtualization kvm net
[Documentation on labels]
Reported-by: syzbot+40e28a8bd59d10ed0c42@syzkaller.appspotmail.com
First crash: 1886d, last: 1856d
Discussions (2)
Title Replies (including bot) Last reply
INFO: task hung in vhost_init_device_iotlb 3 (4) 2019/07/02 07:23
Reminder: 2 open syzbot bugs in vhost subsystem 4 (4) 2019/07/02 07:18

Sample crash report:
protocol 88fb is buggy, dev hsr_slave_1
protocol 88fb is buggy, dev hsr_slave_0
protocol 88fb is buggy, dev hsr_slave_1
protocol 88fb is buggy, dev hsr_slave_0
protocol 88fb is buggy, dev hsr_slave_1
INFO: task syz-executor.5:15648 blocked for more than 140 seconds.
      Not tainted 5.0.0-rc8+ #88
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5  D27344 15648  14052 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2844 [inline]
 __schedule+0x817/0x1cc0 kernel/sched/core.c:3485
 schedule+0x92/0x180 kernel/sched/core.c:3529
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3587
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x726/0x1310 kernel/locking/mutex.c:1072
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
 vhost_init_device_iotlb+0x124/0x280 drivers/vhost/vhost.c:1607
 vhost_net_set_features drivers/vhost/net.c:1675 [inline]
 vhost_net_ioctl+0x10be/0x1900 drivers/vhost/net.c:1740
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:509 [inline]
 do_vfs_ioctl+0xd6e/0x1390 fs/ioctl.c:696
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457e29
Code: Bad RIP value.
RSP: 002b:00007fc6203b2c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457e29
RDX: 0000000020000080 RSI: 000000004008af00 RDI: 0000000000000003
RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc6203b36d4
R13: 00000000004c26a6 R14: 00000000004d5120 R15: 00000000ffffffff

Showing all locks held in the system:
1 lock held by khungtaskd/1040:
 #0: 00000000578ac682 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4389
1 lock held by rsyslogd/7548:
 #0: 00000000c6bc1a46 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:795
2 locks held by getty/7638:
 #0: 000000001397cf5f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 00000000f0e7074b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/7639:
 #0: 000000000606c3f3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 000000002d0a2f56 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/7640:
 #0: 00000000765ee70c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 00000000019c34a2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/7641:
 #0: 0000000030935be0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 00000000a7456e30 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/7642:
 #0: 00000000e0618db2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 0000000068e652ee (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/7643:
 #0: 00000000af65c654 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 00000000784bdf64 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/7644:
 #0: 00000000db0e2d0a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 000000006af326ad (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by syz-executor.5/15648:
 #0: 00000000b19b3344 (&dev->mutex#4){+.+.}, at: vhost_net_set_features drivers/vhost/net.c:1669 [inline]
 #0: 00000000b19b3344 (&dev->mutex#4){+.+.}, at: vhost_net_ioctl+0x1cc/0x1900 drivers/vhost/net.c:1740
 #1: 000000006c3078c5 (&vq->mutex){+.+.}, at: vhost_init_device_iotlb+0x124/0x280 drivers/vhost/vhost.c:1607
1 lock held by vhost-15630/15631:

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

NMI backtrace for cpu 1
CPU: 1 PID: 1040 Comm: khungtaskd Not tainted 5.0.0-rc8+ #88
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1be/0x236 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline]
 watchdog+0x9df/0xee0 kernel/hung_task.c:287
 kthread+0x357/0x430 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 15631 Comm: vhost-15630 Not tainted 5.0.0-rc8+ #88
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__sanitizer_cov_trace_pc+0x26/0x50 kernel/kcov.c:101
Code: 90 90 90 90 55 48 89 e5 48 8b 75 08 65 48 8b 04 25 40 ee 01 00 65 8b 15 98 0e 92 7e 81 e2 00 01 1f 00 75 2b 8b 90 d8 12 00 00 <83> fa 02 75 20 48 8b 88 e0 12 00 00 8b 80 dc 12 00 00 48 8b 11 48
RSP: 0018:ffff88808b5ffa98 EFLAGS: 00000246
RAX: ffff88804ca9a080 RBX: ffff8880a0446e00 RCX: ffffffff853d3a5e
RDX: 0000000000000000 RSI: ffffffff853d3a1a RDI: 0000000000000006
RBP: ffff88808b5ffa98 R08: ffff88804ca9a080 R09: ffffed100b77064f
R10: ffff88808b5ffb68 R11: ffff88805bb83277 R12: 0000000000000010
R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffff600400 CR3: 00000000948e0000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 iotlb_access_ok+0x40a/0x540 drivers/vhost/vhost.c:1240
 vq_iotlb_prefetch+0x114/0x230 drivers/vhost/vhost.c:1255
 handle_rx+0x149/0x1900 drivers/vhost/net.c:1143
 handle_rx_net+0x19/0x20 drivers/vhost/net.c:1285
 vhost_worker+0x2a2/0x4a0 drivers/vhost/vhost.c:362
 kthread+0x357/0x430 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/02/27 05:02 upstream 7d762d69145a f2468c12 .config console log report ci-upstream-kasan-gce-smack-root
2019/01/28 03:04 upstream 983542434e6b c73f090a .config console log report ci-upstream-kasan-gce-selinux-root
2019/02/09 11:14 linux-next a46228f6598a fa6c7b70 .config console log report ci-upstream-linux-next-kasan-gce-root
* Struck through repros no longer work on HEAD.