syzbot


INFO: task hung in nmi_cpu_backtrace

Status: auto-closed as invalid on 2020/05/02 01:19
Reported-by: syzbot+3ce5f554ebde7c90b1c6@syzkaller.appspotmail.com
First crash: 916d, last: 916d
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in nmi_cpu_backtrace 7 1463d 1461d 0/22 auto-closed as invalid on 2019/02/22 10:26
android-49 INFO: task hung in nmi_cpu_backtrace 3 1431d 1607d 0/3 auto-closed as invalid on 2019/02/22 13:59

Sample crash report:
audit: type=1400 audit(1578014227.045:114): avc:  denied  { map } for  pid=25356 comm="sh" path="/bin/dash" dev="sda1" ino=1473 scontext=system_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1
INFO: task syz-executor.0:25351 blocked for more than 140 seconds.
      Not tainted 4.14.161-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

Showing all locks held in the system:
1 lock held by khungtaskd/1045:
 #0:  (tasklist_lock){.+.+}, at: [<ffffffff8148c8d8>] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4544
2 locks held by getty/7186:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff86650bc3>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff83492216>] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156
2 locks held by getty/7187:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff86650bc3>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff83492216>] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156
2 locks held by getty/7188:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff86650bc3>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff83492216>] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156
2 locks held by getty/7189:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff86650bc3>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff83492216>] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156
2 locks held by getty/7190:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff86650bc3>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff83492216>] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156
2 locks held by getty/7191:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff86650bc3>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff83492216>] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156
2 locks held by getty/7192:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff86650bc3>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff83492216>] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156

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

NMI backtrace for cpu 0
CPU: 0 PID: 1045 Comm: khungtaskd Not tainted 4.14.161-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x142/0x197 lib/dump_stack.c:58
 nmi_cpu_backtrace.cold+0x57/0x94 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x141/0x189 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:140 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline]
 watchdog+0x5e7/0xb90 kernel/hung_task.c:274
 kthread+0x319/0x430 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 25352 Comm: syz-executor.0 Not tainted 4.14.161-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8880750ee080 task.stack: ffff888063798000
RIP: 0010:rcu_read_unlock_sched_notrace include/linux/rcupdate.h:775 [inline]
RIP: 0010:trace_lock_acquire include/trace/events/lock.h:13 [inline]
RIP: 0010:lock_acquire+0x32e/0x430 kernel/locking/lockdep.c:3993
RSP: 0018:ffff8880aed07dd0 EFLAGS: 00000082
RAX: 0000000000000000 RBX: ffff8880750ee080 RCX: 1ffffffff1066fc0
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff8880750ee8fc
RBP: ffff8880aed07e18 R08: 0000000000000001 R09: 0000000000000000
R10: ffff88821fff7050 R11: 0000000000000001 R12: ffff8880aed25b58
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f8ae306c700(0000) GS:ffff8880aed00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff5a89f000 CR3: 0000000082017000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:152
 __run_hrtimer kernel/time/hrtimer.c:1222 [inline]
 __hrtimer_run_queues+0x2ba/0xbc0 kernel/time/hrtimer.c:1284
 hrtimer_interrupt+0x1d8/0x5d0 kernel/time/hrtimer.c:1318
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1075 [inline]
 smp_apic_timer_interrupt+0x11c/0x5e0 arch/x86/kernel/apic/apic.c:1100
 apic_timer_interrupt+0x96/0xa0 arch/x86/entry/entry_64.S:792
 </IRQ>
RIP: 0010:__sanitizer_cov_trace_pc+0x15/0x60 kernel/kcov.c:65
RSP: 0018:ffff88806379f808 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10
RAX: ffff8880750ee080 RBX: 000000000008a0f7 RCX: ffffc90005a54000
RDX: 0000000080000001 RSI: ffffffff817d4d36 RDI: ffff88806379f840
RBP: ffff88806379f888 R08: ffff88806379fad0 R09: 0000000000000001
R10: 0000000000000000 R11: ffff8880750ee080 R12: 1ffff1100c6f3f04
R13: ffff88806379f860 R14: ffff88807c31cda8 R15: 00007f8ae3b47000
 zap_pte_range mm/memory.c:1315 [inline]
 zap_pmd_range mm/memory.c:1444 [inline]
 zap_pud_range mm/memory.c:1473 [inline]
 zap_p4d_range mm/memory.c:1494 [inline]
 unmap_page_range+0x840/0x19f0 mm/memory.c:1515
 unmap_single_vma+0x15d/0x2c0 mm/memory.c:1560
 unmap_vmas+0xac/0x170 mm/memory.c:1590
 exit_mmap+0x285/0x4e0 mm/mmap.c:3062
 __mmput kernel/fork.c:930 [inline]
 mmput+0x114/0x440 kernel/fork.c:951
 copy_process.part.0+0x3cdc/0x6a70 kernel/fork.c:1975
 copy_process kernel/fork.c:1586 [inline]
 _do_fork+0x19e/0xce0 kernel/fork.c:2070
 SYSC_clone kernel/fork.c:2180 [inline]
 SyS_clone+0x37/0x50 kernel/fork.c:2174
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45a9e9
RSP: 002b:00007f8ae306bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045a9e9
RDX: 9999999999999999 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 000000000075bf20 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f8ae306c6d4
R13: 00000000004c1117 R14: 00000000004d5158 R15: 00000000ffffffff
Code: 65 ff 05 36 48 b9 7e 48 8b 05 67 5c 65 07 e8 fa db 04 00 44 8b 5d c0 85 c0 74 09 80 3d 22 04 65 07 00 74 4f 65 ff 0d 12 48 b9 7e <0f> 85 0d fe ff ff e8 bb 9c b7 ff e9 03 fe ff ff 0f 0b 0f 0b 0f 

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-linux-4-14 2020/01/03 01:19 linux-4.14.y 4c5bf01e16a7 25a0186e .config log report