INFO: task syz.1.27:5273 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.27 state:D stack:27888 pid: 5273 ppid: 5206 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11c3/0x4350 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537 rwsem_down_read_slowpath+0x53e/0x9b0 kernel/locking/rwsem.c:1055 __down_read_common kernel/locking/rwsem.c:1239 [inline] __down_read kernel/locking/rwsem.c:1252 [inline] down_read+0x96/0x2e0 kernel/locking/rwsem.c:1500 user_get_super+0x118/0x240 fs/super.c:850 quotactl_block fs/quota/quota.c:889 [inline] __do_sys_quotactl fs/quota/quota.c:953 [inline] __se_sys_quotactl+0x46f/0x6f0 fs/quota/quota.c:915 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f835ad252f9 RSP: 002b:00007f8359f68028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f835af61080 RCX: 00007f835ad252f9 RDX: 0000000000000000 RSI: 0000200000000900 RDI: ffffffff80000600 RBP: 00007f835adb8d04 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f835af61080 R15: 00007ffd7e3b33a8 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c31ef20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 4 locks held by kworker/u4:2/154: 3 locks held by kworker/u4:3/155: #0: ffff888016c79138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc90002017d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 #2: ffffffff8d43c1c8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:251 2 locks held by getty/3946: #0: ffff88802cba8098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158 3 locks held by kworker/0:4/4220: #0: ffff88814c620938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc90002f7fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 #2: ffffffff8d43c1c8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x1530 net/ipv6/addrconf.c:4113 3 locks held by kworker/1:22/4313: #0: ffff88814c620938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc9000330fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 #2: ffffffff8d43c1c8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x1530 net/ipv6/addrconf.c:4113 1 lock held by syz.1.18/4752: 1 lock held by syz.2.19/4912: 1 lock held by syz.3.20/4915: 1 lock held by syz.4.21/4926: 1 lock held by syz.0.17/4930: 1 lock held by syz.5.22/5096: 1 lock held by syz.6.23/5247: 1 lock held by syz.7.24/5251: 1 lock held by syz.9.26/5255: 1 lock held by syz.8.25/5258: 1 lock held by syz.1.27/5273: #0: ffff88805b2240e0 (&type->s_umount_key#54){.+.+}-{3:3}, at: user_get_super+0x118/0x240 fs/super.c:850 1 lock held by syz.3.29/5336: #0: ffff888022e160e0 (&type->s_umount_key#54){.+.+}-{3:3}, at: user_get_super+0x118/0x240 fs/super.c:850 1 lock held by syz.2.28/5343: #0: ffff888022f780e0 (&type->s_umount_key#54 ){.+.+}-{3:3}, at: user_get_super+0x118/0x240 fs/super.c:850 1 lock held by syz.0.30/5365: #0: ffff8880237fc0e0 (&type->s_umount_key#54){.+.+}-{3:3}, at: user_get_super+0x118/0x240 fs/super.c:850 1 lock held by syz.4.31/5373: #0: ffff8880776b20e0 (&type->s_umount_key#54){.+.+}-{3:3}, at: user_get_super+0x118/0x240 fs/super.c:850 1 lock held by syz.5.32/5394: #0: ffff888079d7e0e0 (&type->s_umount_key#54){.+.+}-{3:3}, at: user_get_super+0x118/0x240 fs/super.c:850 1 lock held by syz.6.33/5451: #0: ffff88805d22e0e0 (&type->s_umount_key#54){.+.+}-{3:3}, at: user_get_super+0x118/0x240 fs/super.c:850 1 lock held by syz.7.34/5459: #0: ffff888023c920e0 (&type->s_umount_key#54){.+.+}-{3:3}, at: user_get_super+0x118/0x240 fs/super.c:850 1 lock held by syz.8.35/5481: #0: ffff8880593100e0 (&type->s_umount_key#54){.+.+}-{3:3}, at: user_get_super+0x118/0x240 fs/super.c:850 1 lock held by syz-executor/5486: #0: ffffffff8d43c1c8 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x256/0x1ba0 net/ipv4/devinet.c:1076 1 lock held by syz-executor/5502: #0: ffffffff8d43c1c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d43c1c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7d6/0xf00 net/core/rtnetlink.c:5685 1 lock held by syz.9.36/5510: #0: ffff88805405a0e0 (&type->s_umount_key#54){.+.+}-{3:3}, at: user_get_super+0x118/0x240 fs/super.c:850 1 lock held by syz.1.37/5515: #0: ffff88805b2240e0 (&type->s_umount_key#54){.+.+}-{3:3}, at: user_get_super+0x118/0x240 fs/super.c:850 2 locks held by syz-executor/5533: #0: ffffffff8d43c1c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d43c1c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7d6/0xf00 net/core/rtnetlink.c:5685 #1: ffffffff8c3239a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #1: ffffffff8c3239a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845 1 lock held by syz-executor/5538: #0: ffffffff8d43c1c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d43c1c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7d6/0xf00 net/core/rtnetlink.c:5685 1 lock held by syz.3.38/5554: #0: ffff888022e160e0 (&type->s_umount_key#54){.+.+}-{3:3}, at: user_get_super+0x118/0x240 fs/super.c:850 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe1b/0xe60 kernel/hung_task.c:369 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 9 Comm: kworker/u4:0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: events_unbound cfg80211_wiphy_work RIP: 0010:rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:331 [inline] RIP: 0010:rcu_is_watching+0xc/0xa0 kernel/rcu/tree.c:1123 Code: 65 e8 5b 41 5e 41 5f 5d c3 e8 10 39 55 08 41 f7 c7 00 02 00 00 75 bd eb bc e8 f0 38 55 08 41 57 41 56 53 65 ff 05 3c d2 9d 7e ef 48 55 08 89 c3 83 f8 08 73 5c 49 bf 00 00 00 00 00 fc ff df RSP: 0018:ffffc90000ce7af8 EFLAGS: 00000283 RAX: 0000000000000000 RBX: ffff88805139cc80 RCX: ffffffff8b1e7c20 RDX: dffffc0000000000 RSI: ffffffff8a2b2be0 RDI: ffffffff8a79c980 RBP: ffff888022e9cc80 R08: ffffffff901cb12f R09: 1ffffffff2039625 R10: dffffc0000000000 R11: fffffbfff2039626 R12: ffffffff89444ab1 R13: ffffea00008ba700 R14: ffff888022e9cc80 R15: ffff888144bf0140 FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055b48a2be770 CR3: 000000005bee9000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_kmem_cache_free include/trace/events/kmem.h:138 [inline] kmem_cache_free+0x14c/0x210 mm/slub.c:3521 kfree_skb include/linux/skbuff.h:1118 [inline] ieee80211_iface_work+0x781/0xc50 net/mac80211/iface.c:1515 cfg80211_wiphy_work+0x224/0x260 net/wireless/core.c:433 process_one_work+0x867/0xff0 kernel/workqueue.c:2310 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287