syzbot

INFO: task syz.2.295:4641 blocked for more than 144 seconds.
      Not tainted 6.1.112-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.295       state:D stack:24512 pid:4641  ppid:4284   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6693
 rwsem_down_read_slowpath kernel/locking/rwsem.c:1094 [inline]
 __down_read_common kernel/locking/rwsem.c:1261 [inline]
 __down_read kernel/locking/rwsem.c:1274 [inline]
 down_read+0x6ff/0xa30 kernel/locking/rwsem.c:1522
 iterate_supers+0xac/0x1e0 fs/super.c:755
 ksys_sync+0xb9/0x1c0 fs/sync.c:102
 __do_sys_sync+0xa/0x10 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f8818f7dff9
RSP: 002b:00007f8819cc2038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f8819135f80 RCX: 00007f8818f7dff9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f8818ff0296 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f8819135f80 R15: 00007fffeea91028
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/0:0/7:
 #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc900000c7d20 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #2: ffff888029301240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x2cd/0x4120 drivers/net/netdevsim/fib.c:1489
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8d32b1d0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8d32b9d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517
3 locks held by kworker/1:1/27:
 #0: ffff888017e88938 ((wq_completion)pm){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc90000a3fd20 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #2: ffff8880282bb190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline]
 #2: ffff8880282bb190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1fe/0x5730 drivers/usb/core/hub.c:5801
1 lock held by khungtaskd/28:
 #0: ffffffff8d32b000 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8d32b000 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8d32b000 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6494
2 locks held by getty/3404:
 #0: ffff88814b0ba098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc900031262f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2198
1 lock held by syz.0.181/4234:
 #0: ffff8880535c20e0 (&type->s_umount_key#47
/1
){+.+.}-{3:3}, at: alloc_super+0x217/0x930 fs/super.c:228
3 locks held by kworker/1:13/4241:
 #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc900033bfd20 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #2: ffff88807917d240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x2cd/0x4120 drivers/net/netdevsim/fib.c:1489
3 locks held by kworker/0:12/4248:
 #0: ffff88814af19938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc9000341fd20 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #2: ffffffff8e4fa7e8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xcc/0x16b0 net/ipv6/addrconf.c:4115
3 locks held by kworker/1:16/4253:
 #0: ffff88814af19938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc9000346fd20 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #2: ffffffff8e4fa7e8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xcc/0x16b0 net/ipv6/addrconf.c:4115
1 lock held by syz.2.295/4641:
 #0: 
ffff8880535c20e0
 (&type->s_umount_key#48){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:755
1 lock held by syz.1.321/4726:
 #0: ffff8880547180e0 (&type->s_umount_key#47/1){+.+.}-{3:3}, at: alloc_super+0x217/0x930 fs/super.c:228
1 lock held by syz.4.825/6208:
 #0: ffff8880535c20e0
 (
&type->s_umount_key#48){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:755
1 lock held by syz.2.1100/6952:
 #0: ffff8880295d00e0 (&type->s_umount_key#47/1){+.+.}-{3:3}, at: alloc_super+0x217/0x930 fs/super.c:228
1 lock held by syz.3.1176/7156:
 #0: ffff88804724e0e0 (&type->s_umount_key#47/1){+.+.}-{3:3}, at: alloc_super+0x217/0x930 fs/super.c:228
3 locks held by syz-executor/7321:
 #0: ffffffff8e4fa7e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8e4fa7e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7c1/0xff0 net/core/rtnetlink.c:6118
 #1: ffff888049fd13e8 (&wg->device_update_lock){+.+.}-{3:3}, at: wg_open+0x224/0x410 drivers/net/wireguard/device.c:49
 #2: ffffffff8d3305f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
 #2: ffffffff8d3305f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x4f0/0x930 kernel/rcu/tree_exp.h:962
1 lock held by syz.0.1235/7336:
 #0: ffff8880535c20e0 (&type->s_umount_key#48){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:755

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

NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.1.112-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1ae/0x3f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
 watchdog+0xf88/0xfd0 kernel/hung_task.c:377
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 3642 Comm: kworker/0:4 Not tainted 6.1.112-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: mld mld_ifc_work
RIP: 0010:__siphash_unaligned+0x0/0x3d0 lib/siphash.c:80
Code: 35 45 71 f9 03 48 c7 c7 c0 ab 2c 8c 5b 41 5c 41 5d 41 5e 41 5f 5d e9 3f 16 04 00 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc <55> 41 57 41 56 41 55 41 54 53 48 83 ec 30 49 89 d7 48 89 f5 48 89
RSP: 0018:ffffc9000415efe8 EFLAGS: 00000282
RAX: ffffffff889a4727 RBX: 0000000000000000 RCX: ffff88802cff5940
RDX: ffffffff97752c40 RSI: 0000000000000048 RDI: ffffc9000415f0a8
RBP: 0000000000000000 R08: ffffffff889a46cf R09: ffffffff889a4383
R10: 0000000000000002 R11: ffff88802cff5940 R12: 1ffff9200082be18
R13: ffffffff97752c40 R14: ffffc9000415f0a8 R15: ffffc9000415f0c4
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9a6bb08178 CR3: 000000007b962000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 siphash include/linux/siphash.h:86 [inline]
 __flow_hash_from_keys net/core/flow_dissector.c:1679 [inline]
 ___skb_get_hash+0x440/0x800 net/core/flow_dissector.c:1701
 __skb_get_hash+0xb3/0x350 net/core/flow_dissector.c:1763
 skb_get_hash include/linux/skbuff.h:1541 [inline]
 udp_flow_src_port include/net/udp.h:207 [inline]
 geneve6_xmit_skb drivers/net/geneve.c:1036 [inline]
 geneve_xmit+0x7f4/0x3550 drivers/net/geneve.c:1121
 __netdev_start_xmit include/linux/netdevice.h:4853 [inline]
 netdev_start_xmit include/linux/netdevice.h:4867 [inline]
 xmit_one net/core/dev.c:3627 [inline]
 dev_hard_start_xmit+0x261/0x8c0 net/core/dev.c:3643
 __dev_queue_xmit+0x1bb1/0x3cf0 net/core/dev.c:4293
 dev_queue_xmit include/linux/netdevice.h:3021 [inline]
 neigh_hh_output include/net/neighbour.h:528 [inline]
 neigh_output include/net/neighbour.h:542 [inline]
 ip6_finish_output2+0xeae/0x15f0 net/ipv6/ip6_output.c:138
 __ip6_finish_output net/ipv6/ip6_output.c:205 [inline]
 ip6_finish_output+0x6a0/0xa80 net/ipv6/ip6_output.c:216
 dst_output include/net/dst.h:444 [inline]
 NF_HOOK+0x167/0x530 include/linux/netfilter.h:302
 mld_sendpack+0x85e/0xde0 net/ipv6/mcast.c:1820
 mld_send_cr net/ipv6/mcast.c:2121 [inline]
 mld_ifc_work+0x7d7/0xc90 net/ipv6/mcast.c:2653
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>