syzbot


INFO: task hung in ip_mc_drop_socket

Status: auto-closed as invalid on 2019/02/22 10:26
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+b1cd477797b530b62c45@syzkaller.appspotmail.com
First crash: 2369d, last: 2369d
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-44 INFO: task hung in ip_mc_drop_socket 1 2385d 2385d 0/2 auto-closed as invalid on 2019/02/22 12:39
upstream INFO: task hung in ip_mc_drop_socket (2) net 5 1082d 1084d 0/28 auto-closed as invalid on 2022/01/18 13:17
linux-4.19 INFO: task hung in ip_mc_drop_socket 1 963d 963d 0/1 auto-closed as invalid on 2022/06/16 11:31
linux-4.19 INFO: task hung in ip_mc_drop_socket (2) 1 717d 717d 0/1 auto-obsoleted due to no activity on 2023/02/17 23:08

Sample crash report:
audit: type=1326 audit(1523607024.536:20979): auid=4294967295 uid=0 gid=0 ses=4294967295 pid=27806 comm="syz-executor2" exe="/root/syz-executor2" sig=0 arch=c000003e syscall=202 compat=0 ip=0x455319 code=0x50000
IPVS: stopping backup sync thread 20377 ...
INFO: task ipvs-b:7:0:20377 blocked for more than 120 seconds.
      Not tainted 4.16.0+ #2
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
ipvs-b:7:0      D26424 20377      2 0x80000000
Call Trace:
 context_switch kernel/sched/core.c:2848 [inline]
 __schedule+0x801/0x1e30 kernel/sched/core.c:3490
 schedule+0xef/0x430 kernel/sched/core.c:3549
 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3607
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0xe38/0x17f0 kernel/locking/mutex.c:893
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
 ip_mc_drop_socket+0x8f/0x270 net/ipv4/igmp.c:2643
 inet_release+0x4e/0x1f0 net/ipv4/af_inet.c:413
 sock_release+0x96/0x1b0 net/socket.c:594
 sync_thread_backup+0x63a/0x698 net/netfilter/ipvs/ip_vs_sync.c:1770
 kthread+0x345/0x410 kernel/kthread.c:238
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:411

Showing all locks held in the system:
3 locks held by kworker/1:1/24:
 #0: 00000000656e2300 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: __write_once_size include/linux/compiler.h:215 [inline]
 #0: 00000000656e2300 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: 00000000656e2300 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline]
 #0: 00000000656e2300 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:57 [inline]
 #0: 00000000656e2300 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline]
 #0: 00000000656e2300 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0: 00000000656e2300 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: process_one_work+0xaef/0x1b50 kernel/workqueue.c:2116
 #1: 0000000017f5afeb ((addr_chk_work).work){+.+.}, at: process_one_work+0xb46/0x1b50 kernel/workqueue.c:2120
 #2: 00000000864ee988 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
2 locks held by khungtaskd/890:
 #0: 000000007e23833c (rcu_read_lock){....}, at: check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
 #0: 000000007e23833c (rcu_read_lock){....}, at: watchdog+0x1ff/0xf60 kernel/hung_task.c:249
 #1: 0000000061d832b7 (tasklist_lock){.+.+}, at: debug_show_all_locks+0xde/0x34a kernel/locking/lockdep.c:4470
2 locks held by getty/4497:
 #0: 00000000655f8dae (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 00000000c33c88a8 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131
2 locks held by getty/4498:
 #0: 0000000017e3b228 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 00000000e9238b2b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131
2 locks held by getty/4499:
 #0: 00000000171a5be8 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 0000000036e3babf (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131
2 locks held by getty/4500:
 #0: 00000000504bea56 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 000000006302d83f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131
2 locks held by getty/4501:
 #0: 0000000038e6210b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 00000000d36be0a2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131
2 locks held by getty/4502:
 #0: 00000000f28399a2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 00000000d716fb22 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131
2 locks held by getty/4503:
 #0: 000000009620c246 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 0000000043e965ff (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131
1 lock held by ipvs-b:7:0/20377:
 #0: 00000000864ee988 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
2 locks held by syz-executor5/27811:
 #0: 00000000864ee988 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
 #1: 00000000f5524889 (ipvs->sync_mutex){+.+.}, at: do_ip_vs_set_ctl+0x562/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor5/27842:
 #0: 00000000f5524889 (ipvs->sync_mutex){+.+.}, at: do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syz-executor5/27844:
 #0: 00000000864ee988 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
1 lock held by syz-executor5/27847:
 #0: 00000000f5524889 (ipvs->sync_mutex){+.+.}, at: do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syz-executor5/27848:
 #0: 00000000864ee988 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
2 locks held by syz-executor5/27849:
 #0: 0000000058d11033 (vlan_ioctl_mutex){+.+.}, at: sock_ioctl+0x3ab/0x680 net/socket.c:1057
 #1: 00000000864ee988 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
1 lock held by syz-executor5/27850:
 #0: 00000000f5524889 (ipvs->sync_mutex){+.+.}, at: do_ip_vs_set_ctl+0x339/0x1d30 net/netfilter/ipvs/ip_vs_ctl.c:2393
1 lock held by syz-executor5/27851:
 #0: 00000000864ee988 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
1 lock held by syz-executor5/27854:
 #0: 00000000864ee988 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
1 lock held by syz-executor0/27843:
 #0: 00000000864ee988 (rtnl_mutex){+.+.}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: 00000000864ee988 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x40a/0xc10 net/core/rtnetlink.c:4643
1 lock held by syz-executor4/27834:
 #0: 00000000864ee988 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
1 lock held by syz-executor4/27853:
 #0: 00000000864ee988 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74

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

NMI backtrace for cpu 0
CPU: 0 PID: 890 Comm: khungtaskd Not tainted 4.16.0+ #2
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+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_all_cpu_backtrace include/linux/nmi.h:138 [inline]
 check_hung_task kernel/hung_task.c:132 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline]
 watchdog+0xc10/0xf60 kernel/hung_task.c:249
 kthread+0x345/0x410 kernel/kthread.c:238
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:411
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.16.0+ #2
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:mark_irqflags kernel/locking/lockdep.c:3011 [inline]
RIP: 0010:__lock_acquire+0x606/0x5130 kernel/locking/lockdep.c:3388
RSP: 0018:ffff8801db1076d0 EFLAGS: 00000002
RAX: 000000000000000e RBX: 000000000000003a RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffff8801d9ed8b78 RDI: ffff8801d9ed8b99
RBP: ffff8801db107a60 R08: 0000000000000001 R09: 0000000000000000
R10: ffff8801d9ed8b78 R11: ffff8801d9ed8340 R12: ffff8801d9ed8b9a
R13: 0000000000000000 R14: 000000000000000e R15: ffff8801d9ed8b64
FS:  0000000000000000(0000) GS:ffff8801db100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f05a5e1d000 CR3: 00000001c817c000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920
 seqcount_lockdep_reader_access include/linux/seqlock.h:81 [inline]
 read_seqcount_begin include/linux/seqlock.h:164 [inline]
 ktime_get+0x146/0x430 kernel/time/timekeeping.c:738
 tick_nohz_irq_enter kernel/time/tick-sched.c:1237 [inline]
 tick_irq_enter+0x83/0x390 kernel/time/tick-sched.c:1258
 irq_enter+0xb6/0xd0 kernel/softirq.c:346
 scheduler_ipi+0x39b/0xa30 kernel/sched/core.c:1768
 smp_reschedule_interrupt+0xed/0x660 arch/x86/kernel/smp.c:277
 reschedule_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:886
 </IRQ>
RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54
RSP: 0018:ffff8801d9ee7c38 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff02
RAX: dffffc0000000000 RBX: 1ffff1003b3dcf8a RCX: 0000000000000000
RDX: 1ffffffff11630f0 RSI: 0000000000000001 RDI: ffffffff88b18780
RBP: ffff8801d9ee7c38 R08: ffffed003b6246c3 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001
R13: ffff8801d9ee7cf0 R14: ffffffff8958d520 R15: 0000000000000000
 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline]
 default_idle+0xc2/0x440 arch/x86/kernel/process.c:354
 arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:345
 default_idle_call+0x6d/0x90 kernel/sched/idle.c:93
 cpuidle_idle_call kernel/sched/idle.c:153 [inline]
 do_idle+0x395/0x560 kernel/sched/idle.c:262
 cpu_startup_entry+0x104/0x120 kernel/sched/idle.c:368
 start_secondary+0x426/0x5b0 arch/x86/kernel/smpboot.c:267
 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:242
Code: e2 07 38 d0 7f 08 84 c0 0f 85 10 0e 00 00 41 0f b6 42 22 45 84 ed 0f 88 c0 00 00 00 41 8b 93 04 08 00 00 a8 03 0f 84 20 07 00 00 <85> d2 0f 85 a3 0f 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 fa 

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/04/13 08:13 upstream 16e205cf42da 0a0c5db6 .config console log report ci-upstream-kasan-gce
* Struck through repros no longer work on HEAD.