syzbot


INFO: task hung in ppp_exit_net

Status: auto-closed as invalid on 2022/09/27 15:01
Subsystems: ppp
[Documentation on labels]
First crash: 637d, last: 637d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in ppp_exit_net (2) ppp 1 388d 388d 0/26 auto-obsoleted due to no activity on 2023/06/04 05:29
upstream INFO: task hung in ppp_exit_net (3) ppp 1 225d 225d 0/26 auto-obsoleted due to no activity on 2023/11/13 21:08

Sample crash report:
INFO: task kworker/u4:2:42 blocked for more than 143 seconds.
      Not tainted 5.19.0-rc3-syzkaller-00158-g5a478a653b4c #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:2    state:D stack:26056 pid:   42 ppid:     2 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5146 [inline]
 __schedule+0xa00/0x4b50 kernel/sched/core.c:6458
 schedule+0xd2/0x1f0 kernel/sched/core.c:6530
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6589
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0xa70/0x1350 kernel/locking/mutex.c:747
 ppp_exit_net+0x17f/0x590 drivers/net/ppp/ppp_generic.c:1129
 ops_exit_list+0xb0/0x170 net/core/net_namespace.c:162
 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:594
 process_one_work+0x996/0x1610 kernel/workqueue.c:2289
 worker_thread+0x665/0x1080 kernel/workqueue.c:2436
 kthread+0x2e9/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302
 </TASK>
INFO: task syz-executor.2:11372 blocked for more than 143 seconds.
      Not tainted 5.19.0-rc3-syzkaller-00158-g5a478a653b4c #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.2  state:D stack:28408 pid:11372 ppid:  3618 flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5146 [inline]
 __schedule+0xa00/0x4b50 kernel/sched/core.c:6458
 schedule+0xd2/0x1f0 kernel/sched/core.c:6530
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6589
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0xa70/0x1350 kernel/locking/mutex.c:747
 __tun_chr_ioctl+0x64f/0x3da0 drivers/net/tun.c:3068
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7fbac0889109
RSP: 002b:00007fbac19e2168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fbac099bf60 RCX: 00007fbac0889109
RDX: 0000000020000200 RSI: 00000000400454ca RDI: 0000000000000003
RBP: 00007fbac08e305d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fffc896b68f R14: 00007fbac19e2300 R15: 0000000000022000
 </TASK>
INFO: task syz-executor.2:11380 blocked for more than 143 seconds.
      Not tainted 5.19.0-rc3-syzkaller-00158-g5a478a653b4c #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.2  state:D stack:29512 pid:11380 ppid:  3618 flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5146 [inline]
 __schedule+0xa00/0x4b50 kernel/sched/core.c:6458
 schedule+0xd2/0x1f0 kernel/sched/core.c:6530
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6589
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0xa70/0x1350 kernel/locking/mutex.c:747
 tun_set_queue drivers/net/tun.c:2940 [inline]
 __tun_chr_ioctl+0x4b6/0x3da0 drivers/net/tun.c:3061
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7fbac0889109
RSP: 002b:00007fbac19a0168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fbac099c100 RCX: 00007fbac0889109
RDX: 0000000020000340 RSI: 00000000400454d9 RDI: 0000000000000003
RBP: 00007fbac08e305d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fffc896b68f R14: 00007fbac19a0300 R15: 0000000000022000
 </TASK>
INFO: task syz-executor.2:11382 blocked for more than 143 seconds.
      Not tainted 5.19.0-rc3-syzkaller-00158-g5a478a653b4c #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.2  state:D stack:27888 pid:11382 ppid:  3618 flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5146 [inline]
 __schedule+0xa00/0x4b50 kernel/sched/core.c:6458
 schedule+0xd2/0x1f0 kernel/sched/core.c:6530
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6589
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0xa70/0x1350 kernel/locking/mutex.c:747
 rtnl_lock net/core/rtnetlink.c:74 [inline]
 rtnetlink_rcv_msg+0x3e5/0xc90 net/core/rtnetlink.c:6086
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2501
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:734
 ____sys_sendmsg+0x6eb/0x810 net/socket.c:2488
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2542
 __sys_sendmsg net/socket.c:2571 [inline]
 __do_sys_sendmsg net/socket.c:2580 [inline]
 __se_sys_sendmsg net/socket.c:2578 [inline]
 __x64_sys_sendmsg+0x132/0x220 net/socket.c:2578
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7fbac0889109
RSP: 002b:00007fbac197f168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fbac099c1d0 RCX: 00007fbac0889109
RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000004
RBP: 00007fbac08e305d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fffc896b68f R14: 00007fbac197f300 R15: 0000000000022000
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
 #0: ffffffff8bd86ba0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6491
4 locks held by kworker/u4:2/42:
 #0: ffff8880119bd938 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff8880119bd938 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
 #0: ffff8880119bd938 ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline]
 #0: ffff8880119bd938 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline]
 #0: ffff8880119bd938 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline]
 #0: ffff8880119bd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x87a/0x1610 kernel/workqueue.c:2260
 #1: ffffc90000b37da8 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8ae/0x1610 kernel/workqueue.c:2264
 #2: ffffffff8d57b110 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xb00 net/core/net_namespace.c:556
 #3: ffffffff8d58e828 (rtnl_mutex){+.+.}-{3:3}, at: ppp_exit_net+0x17f/0x590 drivers/net/ppp/ppp_generic.c:1129
2 locks held by getty/3291:
 #0: ffff888026a73098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:244
 #1: ffffc90002d162e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xe50/0x13c0 drivers/tty/n_tty.c:2124
3 locks held by kworker/u4:9/4399:
3 locks held by kworker/1:26/5030:
 #0: ffff88814a2d7d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff88814a2d7d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
 #0: ffff88814a2d7d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline]
 #0: ffff88814a2d7d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline]
 #0: ffff88814a2d7d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline]
 #0: ffff88814a2d7d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x87a/0x1610 kernel/workqueue.c:2260
 #1: ffffc90009bbfda8 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x1610 kernel/workqueue.c:2264
 #2: ffffffff8d58e828 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xe/0x20 net/ipv6/addrconf.c:4616
3 locks held by kworker/1:30/5035:
 #0: ffff888011864d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff888011864d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
 #0: ffff888011864d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline]
 #0: ffff888011864d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline]
 #0: ffff888011864d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline]
 #0: ffff888011864d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x87a/0x1610 kernel/workqueue.c:2260
 #1: ffffc90009fd7da8 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x8ae/0x1610 kernel/workqueue.c:2264
 #2: ffffffff8d58e828 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:75
3 locks held by kworker/0:35/10431:
 #0: ffff88814a2d7d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff88814a2d7d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
 #0: ffff88814a2d7d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline]
 #0: ffff88814a2d7d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline]
 #0: ffff88814a2d7d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline]
 #0: ffff88814a2d7d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x87a/0x1610 kernel/workqueue.c:2260
 #1: ffffc9000547fda8 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x1610 kernel/workqueue.c:2264
 #2: ffffffff8d58e828 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xe/0x20 net/ipv6/addrconf.c:4616
1 lock held by syz-executor.3/11349:
 #0: ffffffff8d58e828 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:697 [inline]
 #0: ffffffff8d58e828 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3a/0x180 drivers/net/tun.c:3454
1 lock held by syz-executor.2/11372:
 #0: ffffffff8d58e828 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x64f/0x3da0 drivers/net/tun.c:3068
1 lock held by syz-executor.2/11380:
 #0: ffffffff8d58e828 (rtnl_mutex){+.+.}-{3:3}, at: tun_set_queue drivers/net/tun.c:2940 [inline]
 #0: ffffffff8d58e828 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x4b6/0x3da0 drivers/net/tun.c:3061
1 lock held by syz-executor.2/11382:
 #0: ffffffff8d58e828 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8d58e828 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3e5/0xc90 net/core/rtnetlink.c:6086

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

NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted 5.19.0-rc3-syzkaller-00158-g5a478a653b4c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1e6/0x230 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
 watchdog+0xc22/0xf90 kernel/hung_task.c:378
 kthread+0x2e9/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 305 Comm: kworker/u4:5 Not tainted 5.19.0-rc3-syzkaller-00158-g5a478a653b4c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x60 kernel/kcov.c:200
Code: 81 e1 00 01 00 00 65 48 8b 14 25 80 6f 02 00 a9 00 01 ff 00 74 0e 85 c9 74 35 8b 82 a4 15 00 00 85 c0 74 2b 8b 82 80 15 00 00 <83> f8 02 75 20 48 8b 8a 88 15 00 00 8b 92 84 15 00 00 48 8b 01 48
RSP: 0018:ffffc90002cbf968 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 000000013fe64067 RCX: 0000000000000000
RDX: ffff88801baf9d80 RSI: ffffffff81b37a3a RDI: 0000000000000007
RBP: 000000000aaaaaaa R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 000ffffffffff000
R13: ffff888140168000 R14: 000000013fe64007 R15: ffff888140168000
FS:  0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005582a8a80600 CR3: 000000000ba8e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 pud_pgtable arch/x86/include/asm/pgtable.h:839 [inline]
 pmd_offset include/linux/pgtable.h:111 [inline]
 pmd_alloc include/linux/mm.h:2255 [inline]
 walk_to_pmd+0x13a/0x2a0 mm/memory.c:1815
 __get_locked_pte+0x23/0x270 mm/memory.c:1826
 get_locked_pte include/linux/mm.h:2132 [inline]
 __text_poke+0x1b3/0x8e0 arch/x86/kernel/alternative.c:1052
 text_poke arch/x86/kernel/alternative.c:1137 [inline]
 text_poke_bp_batch+0x382/0x6c0 arch/x86/kernel/alternative.c:1432
 text_poke_flush arch/x86/kernel/alternative.c:1589 [inline]
 text_poke_flush arch/x86/kernel/alternative.c:1586 [inline]
 text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1596
 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146
 jump_label_update+0x32f/0x410 kernel/jump_label.c:830
 static_key_enable_cpuslocked+0x1b1/0x260 kernel/jump_label.c:177
 static_key_enable+0x16/0x20 kernel/jump_label.c:190
 toggle_allocation_gate mm/kfence/core.c:808 [inline]
 toggle_allocation_gate+0x100/0x390 mm/kfence/core.c:800
 process_one_work+0x996/0x1610 kernel/workqueue.c:2289
 worker_thread+0x665/0x1080 kernel/workqueue.c:2436
 kthread+0x2e9/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302
 </TASK>
----------------
Code disassembly (best guess):
   0:	81 e1 00 01 00 00    	and    $0x100,%ecx
   6:	65 48 8b 14 25 80 6f 	mov    %gs:0x26f80,%rdx
   d:	02 00
   f:	a9 00 01 ff 00       	test   $0xff0100,%eax
  14:	74 0e                	je     0x24
  16:	85 c9                	test   %ecx,%ecx
  18:	74 35                	je     0x4f
  1a:	8b 82 a4 15 00 00    	mov    0x15a4(%rdx),%eax
  20:	85 c0                	test   %eax,%eax
  22:	74 2b                	je     0x4f
  24:	8b 82 80 15 00 00    	mov    0x1580(%rdx),%eax
* 2a:	83 f8 02             	cmp    $0x2,%eax <-- trapping instruction
  2d:	75 20                	jne    0x4f
  2f:	48 8b 8a 88 15 00 00 	mov    0x1588(%rdx),%rcx
  36:	8b 92 84 15 00 00    	mov    0x1584(%rdx),%edx
  3c:	48 8b 01             	mov    (%rcx),%rax
  3f:	48                   	rex.W

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/06/29 14:50 net-old 5a478a653b4c 1434eec0 .config console log report info ci-upstream-net-this-kasan-gce INFO: task hung in ppp_exit_net
* Struck through repros no longer work on HEAD.