INFO: task syz.2.3970:22671 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.3970 state:D stack:27328 pid:22671 tgid:22653 ppid:19635 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5533 [inline] __schedule+0x17db/0x58f0 kernel/sched/core.c:7284 __schedule_loop kernel/sched/core.c:7361 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7376 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821 nfsd_nl_listener_set_doit+0x53d/0x1ab0 fs/nfsd/nfsctl.c:2057 genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2572 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1916 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800 __sock_sendmsg net/socket.c:815 [inline] ____sys_sendmsg+0x54e/0x850 net/socket.c:2712 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2766 __sys_sendmsg net/socket.c:2798 [inline] __do_sys_sendmsg net/socket.c:2803 [inline] __se_sys_sendmsg net/socket.c:2801 [inline] __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2801 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f97fe39e159 RSP: 002b:00007f97fc5f6028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f97fe626540 RCX: 00007f97fe39e159 RDX: 000000000000c000 RSI: 0000200000000100 RDI: 0000000000000008 RBP: 00007f97fe43506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f97fe6265d8 R14: 00007f97fe626540 R15: 00007ffcde0ed258 Showing all locks held in the system: locks held by khungtaskd/32: 1, last CPU#0: #0: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871 locks held by kworker/u8:8/1257: 3, last CPU#1: #0: ffff888032284940 ((wq_completion)bat_events){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff888032284940 ((wq_completion)bat_events){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff888032284940 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #0: ffff888032284940 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #1: ffffc9000561fc40 ((work_completion)(&(&forw_packet_aggr->delayed_work)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc9000561fc40 ((work_completion)(&(&forw_packet_aggr->delayed_work)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc9000561fc40 ((work_completion)(&(&forw_packet_aggr->delayed_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #1: ffffc9000561fc40 ((work_completion)(&(&forw_packet_aggr->delayed_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #2: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #2: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #2: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline] #2: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495 locks held by getty/5375: 2, on CPU#1: #0: ffff888035e860a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211 locks held by udevd/16112: 1, on CPU#0: #0: ffff888067b83350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:990 locks held by syz.2.3970/22656: 2, on CPU#0: #0: ffffffff902c61c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8f09f900 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x53d/0x1ab0 fs/nfsd/nfsctl.c:2057 locks held by syz.2.3970/22671: 2, on CPU#1: #0: ffffffff902c61c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8f09f900 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x53d/0x1ab0 fs/nfsd/nfsctl.c:2057 locks held by syz.3.4276/23973: 3, on CPU#0: #0: ffffffff902c61c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffff88807ff5b6e8 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: __netlink_dump_start+0xf4/0x7b0 net/netlink/af_netlink.c:2426 #2: ffffffff8f09f900 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_svc_export_get_reqs_dumpit+0xf7/0xc40 fs/nfsd/export.c:674 locks held by syz.4.4329/24175: 3, on CPU#1: #0: ffffffff902c61c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffff88803266e6e8 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: __netlink_dump_start+0xf4/0x7b0 net/netlink/af_netlink.c:2426 #2: ffffffff8f09f900 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_rpc_status_get_dumpit+0xf0/0x1560 fs/nfsd/nfsctl.c:1521 locks held by syz-executor/24449: 2, last CPU#0: #0: ffff8880325e02e0 (&xt[i].mutex){+.+.}-{4:4}, at: xt_find_table_lock+0x55/0x400 net/netfilter/x_tables.c:1336 #1: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline] #1: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495 locks held by syz.5.5050/27430: 1, last CPU#1: #0: ffff888076b74918 (&p->pi_lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2d/0x160 kernel/sched/core.c:677 locks held by syz.0.5054/27450: 2, last CPU#1: #0: ffff88807aa4b6b8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:600 [inline] #0: ffff88807aa4b6b8 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x1a4/0x9f0 mm/mmap.c:1299 #1: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240 mm/pgtable-generic.c:290 locks held by syz.1.5055/27444: 2, last CPU#1: #0: ffff88807aa4d038 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:600 [inline] #0: ffff88807aa4d038 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x1a4/0x9f0 mm/mmap.c:1299 #1: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240 mm/pgtable-generic.c:290 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 32 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123 nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66 trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 27444 Comm: syz.1.5055 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x80 kernel/kcov.c:212 Code: 8b 3d 64 c4 a6 0c 48 89 de 5b e9 43 82 64 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0d f8 c3 cd 11 65 48 8b 15 f8 c3 cd 11 f7 c2 00 01 00 ff RSP: 0018:ffffc90005bff560 EFLAGS: 00000202 RAX: ffffffff82248e5e RBX: ffffea0001725380 RCX: ffff888025789f40 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffea00017253b3 R09: 1ffffd40002e4a76 R10: dffffc0000000000 R11: fffff940002e4a77 R12: ffffea0001725380 R13: dffffc0000000000 R14: 0000000000000001 R15: ffffea00017253b0 FS: 0000000000000000(0000) GS:ffff888124dc6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c32331a CR3: 0000000034738000 CR4: 00000000003526f0 Call Trace: __folio_mod_stat mm/rmap.c:1344 [inline] __folio_remove_rmap mm/rmap.c:1883 [inline] folio_remove_rmap_ptes+0x56e/0xe40 mm/rmap.c:1910 zap_present_folio_ptes mm/memory.c:1803 [inline] zap_present_ptes mm/memory.c:1861 [inline] do_zap_pte_range mm/memory.c:1963 [inline] zap_pte_range mm/memory.c:2065 [inline] zap_pmd_range mm/memory.c:2151 [inline] zap_pud_range mm/memory.c:2179 [inline] zap_p4d_range mm/memory.c:2200 [inline] __zap_vma_range+0x2302/0x4f80 mm/memory.c:2240 unmap_vmas+0x390/0x550 mm/memory.c:2309 exit_mmap+0x293/0x9f0 mm/mmap.c:1315 __mmput+0x118/0x420 kernel/fork.c:1193 exit_mm+0x221/0x2d0 kernel/exit.c:618 do_exit+0x6cd/0x2360 kernel/exit.c:1000 do_group_exit+0x22d/0x2f0 kernel/exit.c:1155 __do_sys_exit_group kernel/exit.c:1166 [inline] __se_sys_exit_group kernel/exit.c:1164 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1164 x64_sys_call+0x18c6/0x18d0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f575bf9e159 Code: Unable to access opcode bytes at 0x7f575bf9e12f. RSP: 002b:00007fffcae34de8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f575bf9e159 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fffcae34e4c R08: 0000000000000000 R09: 00000000000927c0 R10: 00007f575c226038 R11: 0000000000000246 R12: 0000000000000162 R13: 00000000000927c0 R14: 00000000000c19fa R15: 00007fffcae34ea0