syzbot


INFO: task hung in drain_all_pages (2)

Status: auto-closed as invalid on 2020/09/01 16:02
Reported-by: syzbot+c88f4eaac5c23b4304b8@syzkaller.appspotmail.com
First crash: 792d, last: 785d
similar bugs (3):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 INFO: task hung in drain_all_pages (2) 2 266d 336d 0/1 auto-closed as invalid on 2022/02/03 14:38
linux-4.19 INFO: task hung in drain_all_pages C done 1 860d 890d 1/1 fixed on 2020/03/21 06:12
linux-4.14 INFO: task hung in drain_all_pages C done 1 855d 855d 1/1 fixed on 2020/03/26 13:10

Sample crash report:
NOHZ: local_softirq_pending 08
NOHZ: local_softirq_pending 08
NOHZ: local_softirq_pending 08
NOHZ: local_softirq_pending 08
NOHZ: local_softirq_pending 08
INFO: task khugepaged:1064 blocked for more than 140 seconds.
      Not tainted 4.14.178-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
khugepaged      D26032  1064      2 0x80000000
Call Trace:
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_timeout+0x946/0xe40 kernel/time/timer.c:1723
 do_wait_for_common kernel/sched/completion.c:91 [inline]
 __wait_for_common kernel/sched/completion.c:112 [inline]
 wait_for_common kernel/sched/completion.c:123 [inline]
 wait_for_completion+0x241/0x390 kernel/sched/completion.c:144
 flush_work+0x3f5/0x780 kernel/workqueue.c:2893
 drain_all_pages+0x39a/0x570 mm/page_alloc.c:2536
 __alloc_pages_direct_reclaim mm/page_alloc.c:3616 [inline]
 __alloc_pages_slowpath+0xa16/0x26c0 mm/page_alloc.c:3989
 __alloc_pages_nodemask+0x5d3/0x700 mm/page_alloc.c:4198
 __alloc_pages include/linux/gfp.h:484 [inline]
 __alloc_pages_node include/linux/gfp.h:497 [inline]
 khugepaged_alloc_page+0x75/0x140 mm/khugepaged.c:754
 collapse_huge_page+0xf9/0x2ad0 mm/khugepaged.c:962
 khugepaged_scan_pmd mm/khugepaged.c:1220 [inline]
 khugepaged_scan_mm_slot mm/khugepaged.c:1762 [inline]
 khugepaged_do_scan mm/khugepaged.c:1843 [inline]
 khugepaged+0x20f9/0x2c90 mm/khugepaged.c:1888
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404

Showing all locks held in the system:
5 locks held by kworker/u4:1/22:
 #0:  ("%s""netns"){+.+.}, at: [<ffffffff813b67b7>] work_static include/linux/workqueue.h:199 [inline]
 #0:  ("%s""netns"){+.+.}, at: [<ffffffff813b67b7>] set_work_data kernel/workqueue.c:619 [inline]
 #0:  ("%s""netns"){+.+.}, at: [<ffffffff813b67b7>] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline]
 #0:  ("%s""netns"){+.+.}, at: [<ffffffff813b67b7>] process_one_work+0x727/0x1540 kernel/workqueue.c:2087
 #1:  (net_cleanup_work){+.+.}, at: [<ffffffff813b67f1>] process_one_work+0x761/0x1540 kernel/workqueue.c:2091
 #2:  (net_mutex){+.+.}, at: [<ffffffff84fcb133>] cleanup_net+0x123/0x820 net/core/net_namespace.c:450
 #3:  (rtnl_mutex){+.+.}, at: [<ffffffff85856881>] ip6_tnl_exit_net+0x61/0x530 net/ipv6/ip6_tunnel.c:2261
 #4:  (cpu_hotplug_lock.rw_sem){++++}, at: [<ffffffff84fe4694>] get_online_cpus include/linux/cpu.h:145 [inline]
 #4:  (cpu_hotplug_lock.rw_sem){++++}, at: [<ffffffff84fe4694>] flush_all_backlogs net/core/dev.c:4654 [inline]
 #4:  (cpu_hotplug_lock.rw_sem){++++}, at: [<ffffffff84fe4694>] rollback_registered_many+0x3f4/0xa70 net/core/dev.c:7192
1 lock held by khungtaskd/1057:
 #0:  (tasklist_lock){.+.+}, at: [<ffffffff81465d33>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548
1 lock held by khugepaged/1064:
 #0:  (pcpu_drain_mutex){+.+.}, at: [<ffffffff816f3d2a>] drain_all_pages+0x4a/0x570 mm/page_alloc.c:2493

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

NMI backtrace for cpu 0
CPU: 0 PID: 1057 Comm: khungtaskd Not tainted 4.14.178-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+0x13e/0x194 lib/dump_stack.c:58
 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x139/0x17e lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline]
 watchdog+0x5e2/0xb80 kernel/hung_task.c:274
 kthread+0x30d/0x420 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: 32257 Comm: syz-executor.2 Not tainted 4.14.178-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff88809189c540 task.stack: ffff8880a46d8000
RIP: 0010:snd_pcm_plug_client_channels_buf+0x2ff/0x3f0 sound/core/oss/pcm_plugin.c:606
RSP: 0018:ffff8880a46dfbc0 EFLAGS: 00000a07
RAX: 1ffff11012e3b882 RBX: ffff8880971dc400 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff88808cd12840 RDI: ffff8880971dc414
RBP: 0000000000000008 R08: 0000000000000000 R09: ffffffff8a081b60
R10: ffff8880a46dfc98 R11: ffff88809189c540 R12: ffff88808cd12840
R13: 0000000000000003 R14: dffffc0000000000 R15: 0000000000000000
FS:  00007fe07832f700(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020096000 CR3: 00000001ce90d000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 snd_pcm_oss_read2+0x18f/0x340 sound/core/oss/pcm_oss.c:1472
 snd_pcm_oss_read1 sound/core/oss/pcm_oss.c:1513 [inline]
 snd_pcm_oss_read+0x358/0x5e0 sound/core/oss/pcm_oss.c:2753
 __vfs_read+0xe4/0x610 fs/read_write.c:411
 vfs_read+0x131/0x330 fs/read_write.c:447
 SYSC_read fs/read_write.c:574 [inline]
 SyS_read+0xf2/0x210 fs/read_write.c:567
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45c829
RSP: 002b:00007fe07832ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00000000004fa980 RCX: 000000000045c829
RDX: 00000000000000ce RSI: 00000000200002c0 RDI: 000000000000000b
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000879 R14: 00000000004cb30b R15: 00007fe07832f6d4
Code: 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0 74 08 3c 03 0f 8e 96 00 00 00 48 8d 7b 14 44 89 7b 10 48 89 f8 48 c1 e8 03 46 0f b6 04 30 <48> 89 f8 83 e0 07 83 c0 03 44 38 c0 7c 05 45 84 c0 75 79 8b 44 

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-linux-4-14 2020/05/04 16:01 linux-4.14.y 773e2b1cd56a 58ae5e18 .config log report
ci2-linux-4-14 2020/04/28 13:03 linux-4.14.y 050272a0423e e3ecea2e .config log report