syzbot


INFO: task hung in ppp_release

Status: auto-closed as invalid on 2019/10/08 10:46
Reported-by: syzbot+be80bc1c5cbcfd308239@syzkaller.appspotmail.com
First crash: 1829d, last: 1829d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in ppp_release ppp 1 1414d 1414d 0/26 auto-closed as invalid on 2020/08/28 19:07
upstream INFO: task hung in ppp_release (2) ppp 1 942d 942d 0/26 auto-closed as invalid on 2021/12/13 06:07

Sample crash report:
binder: send failed reply for transaction 17, target dead
binder: send failed reply for transaction 20, target dead
INFO: task syz-executor.3:21194 blocked for more than 140 seconds.
      Not tainted 4.9.168+ #39
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D28280 21194  20055 0x80000002
 ffff8801aa0d97c0 ffff8801cfe48b00 ffff8801db621000 ffff8801ac4caf80
 ffff8801db621018 ffff88016f59f818 ffffffff8280028e 0000000000000000
 0000000000000000 0000000000000000 ffff8801db6218f0 1ffff1002deb3ef2
Call Trace:
 [<0000000052c9cf20>] schedule+0x92/0x1c0 kernel/sched/core.c:3546
 [<0000000091deb787>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3579
 [<00000000c27ce9ce>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<00000000c27ce9ce>] mutex_lock_nested+0x38d/0x920 kernel/locking/mutex.c:621
 [<000000007bba8004>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
 [<00000000b12af0ac>] ppp_release+0xe8/0x1b0 drivers/net/ppp/ppp_generic.c:405
 [<0000000002d8524d>] __fput+0x274/0x720 fs/file_table.c:208
 [<00000000dcb820ac>] ____fput+0x16/0x20 fs/file_table.c:244
 [<000000004a0a992e>] task_work_run+0x108/0x180 kernel/task_work.c:116
 [<00000000799fad31>] exit_task_work include/linux/task_work.h:21 [inline]
 [<00000000799fad31>] do_exit+0x78b/0x2aa0 kernel/exit.c:841
 [<00000000014b87ea>] do_group_exit+0x111/0x300 kernel/exit.c:945
 [<00000000b48c8ec2>] get_signal+0x348/0x1aa0 kernel/signal.c:2380
 [<00000000d04f069c>] do_signal+0x9c/0x1920 arch/x86/kernel/signal.c:807
 [<00000000d77fe2b9>] exit_to_usermode_loop+0x11c/0x160 arch/x86/entry/common.c:158
 [<000000001bd72c6a>] prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline]
 [<000000001bd72c6a>] syscall_return_slowpath arch/x86/entry/common.c:263 [inline]
 [<000000001bd72c6a>] do_syscall_64+0x3f7/0x570 arch/x86/entry/common.c:290
 [<0000000095cbd458>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Showing all locks held in the system:
2 locks held by khungtaskd/24:
 #0:  (rcu_read_lock){......}, at: [<0000000046577eda>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<0000000046577eda>] watchdog+0x13c/0xae0 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<00000000770580c3>] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4339
2 locks held by getty/2027:
 #0:  (&tty->ldisc_sem){++++++}, at: [<000000000b26af38>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377
 #1:  (&ldata->atomic_read_lock){+.+.+.}, at: [<00000000c0f4c21a>] n_tty_read+0x1fe/0x1820 drivers/tty/n_tty.c:2156
3 locks held by kworker/1:0/10443:
 #0:  ("%s"("ipv6_addrconf")){.+.+..}, at: [<0000000018c546bb>] process_one_work+0x790/0x1600 kernel/workqueue.c:2107
 #1:  ((addr_chk_work).work){+.+...}, at: [<00000000badd92aa>] process_one_work+0x7ce/0x1600 kernel/workqueue.c:2111
 #2:  (rtnl_mutex){+.+.+.}, at: [<000000007bba8004>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor.3/21194:
 #0:  (rtnl_mutex){+.+.+.}, at: [<000000007bba8004>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
4 locks held by kworker/u4:33/25254:
 #0:  ("%s""netns"){.+.+.+}, at: [<0000000018c546bb>] process_one_work+0x790/0x1600 kernel/workqueue.c:2107
 #1:  (net_cleanup_work){+.+.+.}, at: [<00000000badd92aa>] process_one_work+0x7ce/0x1600 kernel/workqueue.c:2111
 #2:  (net_mutex){+.+.+.}, at: [<00000000e1760c46>] cleanup_net+0x131/0x8a0 net/core/net_namespace.c:439
 #3:  (rtnl_mutex){+.+.+.}, at: [<000000007bba8004>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
2 locks held by syz-executor.2/28979:
 #0:  (&sb->s_type->i_mutex_key#8){+.+.+.}, at: [<00000000d192b7c3>] inode_lock include/linux/fs.h:768 [inline]
 #0:  (&sb->s_type->i_mutex_key#8){+.+.+.}, at: [<00000000d192b7c3>] __sock_release+0x89/0x2c0 net/socket.c:604
 #1:  (rtnl_mutex){+.+.+.}, at: [<000000007bba8004>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor.2/12609:
 #0:  (rtnl_mutex){+.+.+.}, at: [<000000007bba8004>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor.2/12620:
 #0:  (rtnl_mutex){+.+.+.}, at: [<000000007bba8004>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor.3/12632:
 #0:  (rtnl_mutex){+.+.+.}, at: [<0000000079283a66>] rtnl_lock net/core/rtnetlink.c:70 [inline]
 #0:  (rtnl_mutex){+.+.+.}, at: [<0000000079283a66>] rtnetlink_rcv+0x1c/0x40 net/core/rtnetlink.c:4086
1 lock held by syz-executor.5/12626:
 #0:  (rtnl_mutex){+.+.+.}, at: [<000000007bba8004>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor.5/12627:
 #0:  (rtnl_mutex){+.+.+.}, at: [<000000007bba8004>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70

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

NMI backtrace for cpu 1
CPU: 1 PID: 24 Comm: khungtaskd Not tainted 4.9.168+ #39
 ffff8801d98d7cc8 ffffffff81b4f5d1 0000000000000001 0000000000000000
 0000000000000001 ffffffff81097401 dffffc0000000000 ffff8801d98d7d00
 ffffffff81b5a86c 0000000000000001 0000000000000000 0000000000000001
Call Trace:
 [<00000000f59dcc91>] __dump_stack lib/dump_stack.c:15 [inline]
 [<00000000f59dcc91>] dump_stack+0xc1/0x120 lib/dump_stack.c:51
 [<00000000f09899d1>] nmi_cpu_backtrace.cold+0x47/0x87 lib/nmi_backtrace.c:99
 [<00000000b41fcb9c>] nmi_trigger_cpumask_backtrace+0x124/0x155 lib/nmi_backtrace.c:60
 [<0000000016cbfe19>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<0000000053bd6729>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<0000000053bd6729>] check_hung_task kernel/hung_task.c:125 [inline]
 [<0000000053bd6729>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<0000000053bd6729>] watchdog+0x661/0xae0 kernel/hung_task.c:239
 [<00000000209be693>] kthread+0x278/0x310 kernel/kthread.c:211
 [<00000000eb32ebb0>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 12649 Comm: kworker/0:5 Not tainted 4.9.168+ #39
Workqueue: events_power_efficient gc_workerc
task: 000000002aef4d6e task.stack: 000000005d4aceae
RIP: 0010:[<ffffffff81207a89>] c [<00000000881c40b9>] trace_hardirqs_on_caller+0x109/0x5a0 kernel/locking/lockdep.c:2719
RSP: 0018:ffff8801cae0fb40  EFLAGS: 00000097
RAX: 0000000000000003 RBX: ffffffff841f18c0 RCX: 1ffffffff063f77c
RDX: 0000000000000004 RSI: ffffffff82401e4c RDI: ffff8801aa2d37f8
RBP: ffff8801cae0fb50 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff82401e51
R13: fffffbfff0601200 R14: 0000000000000293 R15: 000000000001b145
FS:  0000000000000000(0000) GS:ffff8801db600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff41180c4fe CR3: 00000001aab52000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Stack:
 dffffc0000000000c 0000000000000000c ffff8801cae0fb60c ffffffff81207f2dc
 ffff8801cae0fbd8c ffffffff82401e51c ffffffff8112f76bc ffffffff830d45a0c
 ffffffff84b7cff8c ffffffff84b7cf40c 00000200a17f5c00c ffff880100010000c
Call Trace:
 [<0000000092b61910>] trace_hardirqs_on+0xd/0x10 kernel/locking/lockdep.c:2743
 [<0000000073412b94>] seqcount_lockdep_reader_access include/linux/seqlock.h:82 [inline]
 [<0000000073412b94>] read_seqcount_begin include/linux/seqlock.h:163 [inline]
 [<0000000073412b94>] nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:325 [inline]
 [<0000000073412b94>] gc_worker+0x451/0x600 net/netfilter/nf_conntrack_core.c:987
 [<00000000658a58a8>] process_one_work+0x88b/0x1600 kernel/workqueue.c:2114
 [<00000000a64605d9>] worker_thread+0x5df/0x11d0 kernel/workqueue.c:2251
 [<00000000209be693>] kthread+0x278/0x310 kernel/kthread.c:211
 [<00000000eb32ebb0>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Code: c00 cfc cff cdf c48 c89 cda c48 cc1 cea c03 c0f cb6 c14 c02 c48 c89 cd8 c83 ce0 c07 c83 cc0 c03 c38 cd0 c7c c08 c84 cd2 c0f c85 c28 c03 c00 c00 c44 c8b c0d c37 c9e cfe c02 c<45> c85 cc9 c0f c85 cc5 c00 c00 c00 c9c c58 c0f c1f c44 c00 c00 cf6 cc4 c02 c0f c85 c

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/04/11 10:45 https://android.googlesource.com/kernel/common android-4.9 286f971000f1 e955ac50 .config console log report ci-android-49-kasan-gce-root
* Struck through repros no longer work on HEAD.