INFO: task syz.3.1284:11505 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.1284 state:D stack:24504 pid:11505 tgid:11501 ppid:5827 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0xfe4/0x5e10 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] schedule+0xdd/0x390 kernel/sched/core.c:6964 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7021 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776 nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1596 genl_family_rcv_msg_doit+0x214/0x300 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x560/0x800 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2550 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa54/0xc30 net/socket.c:2592 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2646 __sys_sendmsg+0x170/0x220 net/socket.c:2678 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f487939aeb9 RSP: 002b:00007f487a1b5028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f4879616180 RCX: 00007f487939aeb9 RDX: 0000000000004000 RSI: 0000200000000480 RDI: 0000000000000005 RBP: 00007f4879408c1f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4879616218 R14: 00007f4879616180 R15: 00007fffd1032878 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e5e3120 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5e3120 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e5e3120 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 3 locks held by kworker/1:3/5868: #0: ffff88813fe15948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232 #1: ffffc9000ae1fc98 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233 #2: ffffffff8e5ef7c0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3816 3 locks held by kworker/0:4/5875: #0: ffff88813fe15948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232 #1: ffffc9000aed7c98 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233 #2: ffffffff8e5ef8f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343 4 locks held by kworker/u10:3/7487: #0: ffff88801c29f148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232 #1: ffffc9000b0b7c98 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233 #2: ffffffff903dcef0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xab/0x830 net/core/net_namespace.c:670 #3: ffffffff8e5ef7c0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3816 2 locks held by syz.1.499/8010: #0: ffff88806128a0e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88806128a0e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88806128a0e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: deactivate_super fs/super.c:506 [inline] #0: ffff88806128a0e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:503 #1: ffffffff8ea472a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:575 5 locks held by kworker/u10:26/10586: 2 locks held by syz.2.1282/11497: #0: ffffffff904a2690 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ea472a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1596 2 locks held by syz.3.1284/11505: #0: ffffffff904a2690 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ea472a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1596 2 locks held by getty/13699: #0: ffff88814d5a50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000455b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211 2 locks held by syz.0.1839/14113: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xcc3/0xfe0 kernel/hung_task.c:515 kthread+0x3b3/0x730 kernel/kthread.c:463 ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 14113 Comm: syz.0.1839 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 RIP: 0010:kasan_save_track+0x27/0x30 mm/kasan/common.c:80 Code: 90 90 90 0f 1f 40 d6 53 48 89 fb 89 f7 be 01 00 00 00 e8 5c ff ff ff 65 48 8b 15 ec 5c 74 11 8b 92 18 06 00 00 89 43 04 89 13 <5b> c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000007958 EFLAGS: 00000282 RAX: 00000000004a0264 RBX: ffff88804b64bd70 RCX: ffff88805fdec250 RDX: 0000000000003721 RSI: 00000000fa2e064b RDI: 0000000000000002 RBP: 0000000000000001 R08: 0000000000102410 R09: 0000000095a10241 R10: 0000000000000001 R11: 0000000000000000 R12: ffff88801f2ef000 R13: 0000000000000820 R14: 0000000000000001 R15: 00000000ffffffff FS: 00007f66d52346c0(0000) GS:ffff8881245e3000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000401000 CR3: 000000003297a000 CR4: 00000000003526f0 Call Trace: unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_node_noprof+0x303/0x880 mm/slub.c:5315 __alloc_skb+0x156/0x410 net/core/skbuff.c:679 skb_copy+0x1ca/0x3a0 net/core/skbuff.c:2163 mac80211_hwsim_tx_frame_no_nl.isra.0+0xbf6/0x1370 drivers/net/wireless/virtual/mac80211_hwsim.c:1891 mac80211_hwsim_tx_frame+0x1f6/0x2a0 drivers/net/wireless/virtual/mac80211_hwsim.c:2264 __mac80211_hwsim_beacon_tx drivers/net/wireless/virtual/mac80211_hwsim.c:2281 [inline] mac80211_hwsim_beacon_tx+0x57e/0xa00 drivers/net/wireless/virtual/mac80211_hwsim.c:2365 __iterate_interfaces+0x2e6/0x650 net/mac80211/util.c:761 ieee80211_iterate_active_interfaces_atomic+0x71/0x1b0 net/mac80211/util.c:797 mac80211_hwsim_beacon+0x105/0x1b0 drivers/net/wireless/virtual/mac80211_hwsim.c:2395 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x516/0x990 kernel/time/hrtimer.c:1841 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1858 handle_softirqs+0x1ea/0x910 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xef/0x150 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0x57b/0x14a0 kernel/smp.c:877 Code: 00 fc ff df 48 8b 54 24 10 49 89 d5 49 89 d4 49 c1 ed 03 41 83 e4 07 49 01 c5 41 83 c4 03 e8 ec 4f 0c 00 f3 90 41 0f b6 45 00 <41> 38 c4 7c 08 84 c0 0f 85 3f 0d 00 00 8b 45 08 31 ff 83 e0 01 41 RSP: 0018:ffffc90002e77760 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffc9000c1bb000 RDX: 0000000000080000 RSI: ffffffff81f9fa94 RDI: ffff88802ba51e80 RBP: ffff8880b8540e00 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003 R13: ffffed10170a81c1 R14: 0000000000000001 R15: ffff8880b843c040 on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1043 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline] flush_tlb_mm_range+0x45f/0x1710 arch/x86/mm/tlb.c:1472 tlb_flush arch/x86/include/asm/tlb.h:23 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:506 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:496 [inline] tlb_flush_mmu mm/mmu_gather.c:404 [inline] tlb_finish_mmu+0x3fe/0x810 mm/mmu_gather.c:530 free_ldt_pgtables+0x151/0x1c0 arch/x86/kernel/ldt.c:411 arch_exit_mmap arch/x86/include/asm/mmu_context.h:234 [inline] exit_mmap+0x121/0xae0 mm/mmap.c:1263 __mmput+0x12a/0x410 kernel/fork.c:1173 mmput+0x67/0x80 kernel/fork.c:1196 kernel_move_pages+0xee0/0x13f0 mm/migrate.c:2597 __do_sys_move_pages mm/migrate.c:2606 [inline] __se_sys_move_pages mm/migrate.c:2601 [inline] __x64_sys_move_pages+0xe0/0x1c0 mm/migrate.c:2601 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f66d439aeb9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f66d5234028 EFLAGS: 00000246 ORIG_RAX: 0000000000000117 RAX: ffffffffffffffda RBX: 00007f66d4616090 RCX: 00007f66d439aeb9 RDX: 0000000000000000 RSI: 0002000000000003 RDI: 0000000000000001 RBP: 00007f66d4408c1f R08: 0000000000000000 R09: 8000400000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f66d4616128 R14: 00007f66d4616090 R15: 00007fffe8001e48