syzbot


INFO: task hung in br_net_exit

Status: auto-closed as invalid on 2022/01/17 14:15
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 406d, last: 405d

Sample crash report:
INFO: task kworker/u4:2:154 blocked for more than 143 seconds.
      Not tainted 5.15.0-rc5-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:2    state:D stack:24992 pid:  154 ppid:     2 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
 context_switch kernel/sched/core.c:4940 [inline]
 __schedule+0xb44/0x5960 kernel/sched/core.c:6287
 schedule+0xd3/0x270 kernel/sched/core.c:6366
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6425
 __mutex_lock_common kernel/locking/mutex.c:669 [inline]
 __mutex_lock+0xa34/0x12f0 kernel/locking/mutex.c:729
 br_net_exit+0x7b/0x190 net/bridge/br.c:350
 ops_exit_list+0xb0/0x160 net/core/net_namespace.c:168
 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:593
 process_one_work+0x9bf/0x16b0 kernel/workqueue.c:2297
 worker_thread+0x658/0x11f0 kernel/workqueue.c:2444
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
INFO: task syz-executor.3:9478 blocked for more than 143 seconds.
      Not tainted 5.15.0-rc5-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.3  state:D stack:26248 pid: 9478 ppid:  6563 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:4940 [inline]
 __schedule+0xb44/0x5960 kernel/sched/core.c:6287
 schedule+0xd3/0x270 kernel/sched/core.c:6366
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6425
 __mutex_lock_common kernel/locking/mutex.c:669 [inline]
 __mutex_lock+0xa34/0x12f0 kernel/locking/mutex.c:729
 ip_tunnel_init_net+0x2d5/0x9d0 net/ipv4/ip_tunnel.c:1069
 vti_init_net+0x2a/0x370 net/ipv4/ip_vti.c:504
 ops_init+0xaf/0x470 net/core/net_namespace.c:140
 setup_net+0x40f/0xa30 net/core/net_namespace.c:326
 copy_net_ns+0x319/0x760 net/core/net_namespace.c:470
 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:226
 ksys_unshare+0x445/0x920 kernel/fork.c:3077
 __do_sys_unshare kernel/fork.c:3151 [inline]
 __se_sys_unshare kernel/fork.c:3149 [inline]
 __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3149
 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+0x44/0xae
RIP: 0033:0x7f62abff2a39
RSP: 002b:00007f62a9568188 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f62ac0f5f60 RCX: 00007f62abff2a39
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000006c060000
RBP: 00007f62ac04cc5f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc0718baaf R14: 00007f62a9568300 R15: 0000000000022000
INFO: task syz-executor.3:9481 blocked for more than 143 seconds.
      Not tainted 5.15.0-rc5-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.3  state:D stack:27216 pid: 9481 ppid:  6563 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:4940 [inline]
 __schedule+0xb44/0x5960 kernel/sched/core.c:6287
 schedule+0xd3/0x270 kernel/sched/core.c:6366
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6425
 __mutex_lock_common kernel/locking/mutex.c:669 [inline]
 __mutex_lock+0xa34/0x12f0 kernel/locking/mutex.c:729
 ip_tunnel_init_net+0x2d5/0x9d0 net/ipv4/ip_tunnel.c:1069
 ops_init+0xaf/0x470 net/core/net_namespace.c:140
 setup_net+0x40f/0xa30 net/core/net_namespace.c:326
 copy_net_ns+0x319/0x760 net/core/net_namespace.c:470
 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:226
 ksys_unshare+0x445/0x920 kernel/fork.c:3077
 __do_sys_unshare kernel/fork.c:3151 [inline]
 __se_sys_unshare kernel/fork.c:3149 [inline]
 __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3149
 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+0x44/0xae
RIP: 0033:0x7f62abff2a39
RSP: 002b:00007f62a9547188 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f62ac0f6020 RCX: 00007f62abff2a39
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000060000000
RBP: 00007f62ac04cc5f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc0718baaf R14: 00007f62a9547300 R15: 0000000000022000
INFO: task syz-executor.5:9496 blocked for more than 144 seconds.
      Not tainted 5.15.0-rc5-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.5  state:D stack:28176 pid: 9496 ppid:  6803 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:4940 [inline]
 __schedule+0xb44/0x5960 kernel/sched/core.c:6287
 schedule+0xd3/0x270 kernel/sched/core.c:6366
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6425
 __mutex_lock_common kernel/locking/mutex.c:669 [inline]
 __mutex_lock+0xa34/0x12f0 kernel/locking/mutex.c:729
 rtnl_lock net/core/rtnetlink.c:72 [inline]
 rtnetlink_rcv_msg+0x3be/0xb80 net/core/rtnetlink.c:5569
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2491
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x86d/0xda0 net/netlink/af_netlink.c:1916
 sock_sendmsg_nosec net/socket.c:704 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:724
 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2409
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2463
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2492
 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+0x44/0xae
RIP: 0033:0x7f6a5e9f8a39
RSP: 002b:00007f6a5bf6e188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f6a5eafbf60 RCX: 00007f6a5e9f8a39
RDX: 0000000000000000 RSI: 0000000020000280 RDI: 0000000000000003
RBP: 00007f6a5ea52c5f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff7c75ec9f R14: 00007f6a5bf6e300 R15: 0000000000022000

Showing all locks held in the system:
1 lock held by khungtaskd/26:
 #0: ffffffff8b981ee0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6446
4 locks held by kworker/u4:2/154:
 #0: ffff888015f8b138 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff888015f8b138 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
 #0: ffff888015f8b138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline]
 #0: ffff888015f8b138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:634 [inline]
 #0: ffff888015f8b138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:661 [inline]
 #0: ffff888015f8b138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x8a3/0x16b0 kernel/workqueue.c:2268
 #1: ffffc900018dfdb0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8d7/0x16b0 kernel/workqueue.c:2272
 #2: ffffffff8d0d5990 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xb00 net/core/net_namespace.c:555
 #3: ffffffff8d0e90e8 (rtnl_mutex){+.+.}-{3:3}, at: br_net_exit+0x7b/0x190 net/bridge/br.c:350
3 locks held by kworker/u4:3/158:
 #0: ffff8880b9d31a58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2b/0x120 kernel/sched/core.c:474
 #1: ffff8880b9d1f9c8 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39d/0x480 kernel/sched/psi.c:880
 #2: ffff8880b9d20258 (&base->lock){..-.}-{2:2}, at: lock_timer_base+0x5a/0x1f0 kernel/time/timer.c:946
3 locks held by kworker/1:2/1054:
 #0: ffff888147b25138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff888147b25138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
 #0: ffff888147b25138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline]
 #0: ffff888147b25138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:634 [inline]
 #0: ffff888147b25138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:661 [inline]
 #0: ffff888147b25138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x8a3/0x16b0 kernel/workqueue.c:2268
 #1: ffffc90004e67db0 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x8d7/0x16b0 kernel/workqueue.c:2272
 #2: ffffffff8d0e90e8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4590
1 lock held by in:imklog/6247:
 #0: ffff888072cc8d70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990
3 locks held by kworker/1:3/7506:
 #0: ffff888010c65d38 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff888010c65d38 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
 #0: ffff888010c65d38 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline]
 #0: ffff888010c65d38 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:634 [inline]
 #0: ffff888010c65d38 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:661 [inline]
 #0: ffff888010c65d38 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x8a3/0x16b0 kernel/workqueue.c:2268
 #1: ffffc90005acfdb0 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work+0x8d7/0x16b0 kernel/workqueue.c:2272
 #2: ffffffff8d0e90e8 (rtnl_mutex){+.+.}-{3:3}, at: reg_check_chans_work+0x83/0xe10 net/wireless/reg.c:2423
2 locks held by syz-executor.3/9478:
 #0: ffffffff8d0d5990 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x2f5/0x760 net/core/net_namespace.c:466
 #1: ffffffff8d0e90e8 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_init_net+0x2d5/0x9d0 net/ipv4/ip_tunnel.c:1069
2 locks held by syz-executor.3/9481:
 #0: ffffffff8d0d5990 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x2f5/0x760 net/core/net_namespace.c:466
 #1: ffffffff8d0e90e8 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_init_net+0x2d5/0x9d0 net/ipv4/ip_tunnel.c:1069
1 lock held by syz-executor.3/9493:
 #0: ffffffff8d0e90e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8d0e90e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3be/0xb80 net/core/rtnetlink.c:5569
1 lock held by syz-executor.5/9496:
 #0: ffffffff8d0e90e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8d0e90e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3be/0xb80 net/core/rtnetlink.c:5569

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

NMI backtrace for cpu 0
CPU: 0 PID: 26 Comm: khungtaskd Not tainted 5.15.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __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:105
 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xc1d/0xf50 kernel/hung_task.c:295
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 2968 Comm: systemd-journal Not tainted 5.15.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:find_stack lib/stackdepot.c:209 [inline]
RIP: 0010:stack_depot_save+0x131/0x4e0 lib/stackdepot.c:281
Code: da 81 e2 ff ff 0f 00 4c 8d 3c d0 4d 8b 37 4d 85 f6 75 11 e9 94 00 00 00 4d 8b 36 4d 85 f6 0f 84 88 00 00 00 41 39 5e 08 75 ee <45> 3b 66 0c 75 e8 31 c0 49 8b 4c c6 18 48 39 4c c5 00 75 da 48 83
RSP: 0018:ffffc9000207f760 EFLAGS: 00000246
RAX: ffff88823b000000 RBX: 0000000034ca8fc3 RCX: 0000000000000003
RDX: 00000000000a8fc3 RSI: 0000000000000dc0 RDI: 00000000f57aabbb
RBP: ffffc9000207f7d0 R08: 000000006293a93c R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 000000000000000c
R13: 000000000000000c R14: ffff88801c079b20 R15: ffff88823b547e18
FS:  00007f3b66a1c8c0(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3b63e38020 CR3: 000000001af14000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 kasan_save_stack+0x32/0x40 mm/kasan/common.c:40
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 __kasan_slab_alloc+0x83/0xb0 mm/kasan/common.c:467
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook mm/slab.h:519 [inline]
 slab_alloc_node mm/slub.c:3206 [inline]
 slab_alloc mm/slub.c:3214 [inline]
 kmem_cache_alloc+0x209/0x390 mm/slub.c:3219
 kmem_cache_zalloc include/linux/slab.h:711 [inline]
 lsm_file_alloc security/security.c:572 [inline]
 security_file_alloc+0x34/0x170 security/security.c:1515
 __alloc_file+0xd8/0x280 fs/file_table.c:106
 alloc_empty_file+0x6d/0x170 fs/file_table.c:150
 path_openat+0xe4/0x2740 fs/namei.c:3547
 do_filp_open+0x1aa/0x400 fs/namei.c:3588
 do_sys_openat2+0x16d/0x4d0 fs/open.c:1200
 do_sys_open fs/open.c:1216 [inline]
 __do_sys_open fs/open.c:1224 [inline]
 __se_sys_open fs/open.c:1220 [inline]
 __x64_sys_open+0x119/0x1c0 fs/open.c:1220
 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+0x44/0xae
RIP: 0033:0x7f3b65fab840
Code: 73 01 c3 48 8b 0d 68 77 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 89 bb 20 00 00 75 10 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 1e f6 ff ff 48 89 04 24
RSP: 002b:00007fffabd5eb58 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007fffabd5ee60 RCX: 00007f3b65fab840
RDX: 00000000000001a0 RSI: 0000000000080042 RDI: 0000560545dcd680
RBP: 000000000000000d R08: 000000000000c0c1 R09: 00000000ffffffff
R10: 0000000000000069 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000560545dc1040 R14: 00007fffabd5ee20 R15: 0000560545dcd4a0
----------------
Code disassembly (best guess), 1 bytes skipped:
   0:	81 e2 ff ff 0f 00    	and    $0xfffff,%edx
   6:	4c 8d 3c d0          	lea    (%rax,%rdx,8),%r15
   a:	4d 8b 37             	mov    (%r15),%r14
   d:	4d 85 f6             	test   %r14,%r14
  10:	75 11                	jne    0x23
  12:	e9 94 00 00 00       	jmpq   0xab
  17:	4d 8b 36             	mov    (%r14),%r14
  1a:	4d 85 f6             	test   %r14,%r14
  1d:	0f 84 88 00 00 00    	je     0xab
  23:	41 39 5e 08          	cmp    %ebx,0x8(%r14)
  27:	75 ee                	jne    0x17
* 29:	45 3b 66 0c          	cmp    0xc(%r14),%r12d <-- trapping instruction
  2d:	75 e8                	jne    0x17
  2f:	31 c0                	xor    %eax,%eax
  31:	49 8b 4c c6 18       	mov    0x18(%r14,%rax,8),%rcx
  36:	48 39 4c c5 00       	cmp    %rcx,0x0(%rbp,%rax,8)
  3b:	75 da                	jne    0x17
  3d:	48                   	rex.W
  3e:	83                   	.byte 0x83

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-net-kasan-gce 2021/10/19 14:15 net-next cb3dc8901ba4 24dc29db .config log report info INFO: task hung in br_net_exit
ci-upstream-net-kasan-gce 2021/10/18 12:25 net-next d40dfa0cebd8 0c5d9412 .config log report info INFO: task hung in br_net_exit
* Struck through repros no longer work on HEAD.