INFO: task syz.1.1481:11739 blocked for more than 208 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.1481 state:D stack:27208 pid:11739 tgid:11739 ppid:5829 task_flags:0x440040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5258 [inline] __schedule+0x150e/0x5070 kernel/sched/core.c:6866 __schedule_loop kernel/sched/core.c:6948 [inline] schedule+0x165/0x360 kernel/sched/core.c:6963 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7020 rwsem_down_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1086 __down_read_common kernel/locking/rwsem.c:1261 [inline] __down_read kernel/locking/rwsem.c:1274 [inline] down_read+0x99/0x2e0 kernel/locking/rwsem.c:1539 filemap_invalidate_lock_shared include/linux/fs.h:1093 [inline] page_cache_ra_order+0x37a/0xe50 mm/readahead.c:494 do_sync_mmap_readahead+0x66a/0x870 mm/filemap.c:3400 filemap_fault+0x6ac/0x1290 mm/filemap.c:3549 __do_fault+0x138/0x390 mm/memory.c:5320 do_shared_fault mm/memory.c:5819 [inline] do_fault mm/memory.c:5893 [inline] do_pte_missing+0x6aa/0x3330 mm/memory.c:4401 handle_pte_fault mm/memory.c:6273 [inline] __handle_mm_fault mm/memory.c:6411 [inline] handle_mm_fault+0x1b26/0x32b0 mm/memory.c:6580 do_user_addr_fault+0xa7c/0x1380 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x82/0x100 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7f0f02e55543 RSP: 002b:00007ffe6d0c6970 EFLAGS: 00010246 RAX: 0000200000000500 RBX: 0000000000000002 RCX: 0000000000000000 RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000555563a393c8 RBP: 00007ffe6d0c6a78 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 00007f0f031e5fac R13: 00007f0f031e5fa0 R14: fffffffffffffffe R15: 00007ffe6d0c6ac0 INFO: task syz.6.1484:11747 blocked for more than 208 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.1484 state:D stack:27496 pid:11747 tgid:11747 ppid:8645 task_flags:0x440040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5258 [inline] __schedule+0x150e/0x5070 kernel/sched/core.c:6866 __schedule_loop kernel/sched/core.c:6948 [inline] schedule+0x165/0x360 kernel/sched/core.c:6963 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7020 rwsem_down_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1086 __down_read_common kernel/locking/rwsem.c:1261 [inline] __down_read kernel/locking/rwsem.c:1274 [inline] down_read+0x99/0x2e0 kernel/locking/rwsem.c:1539 filemap_invalidate_lock_shared include/linux/fs.h:1093 [inline] page_cache_ra_order+0x37a/0xe50 mm/readahead.c:494 do_sync_mmap_readahead+0x66a/0x870 mm/filemap.c:3400 filemap_fault+0x6ac/0x1290 mm/filemap.c:3549 __do_fault+0x138/0x390 mm/memory.c:5320 do_shared_fault mm/memory.c:5819 [inline] do_fault mm/memory.c:5893 [inline] do_pte_missing+0x6aa/0x3330 mm/memory.c:4401 handle_pte_fault mm/memory.c:6273 [inline] __handle_mm_fault mm/memory.c:6411 [inline] handle_mm_fault+0x1b26/0x32b0 mm/memory.c:6580 do_user_addr_fault+0xa7c/0x1380 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x82/0x100 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7f5d665573ad RSP: 002b:00007ffe23122af8 EFLAGS: 00010283 RAX: 00002000000001c0 RBX: 0000000000000004 RCX: 8000000000000044 RDX: 0000000000000044 RSI: 0000001b2fe202a7 RDI: 00002000000001c0 RBP: 00007f5d667e7da0 R08: 0000001b30220000 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000009 R12: 00007f5d667e5fac R13: 00007f5d667e5fa0 R14: fffffffffffffffe R15: 00007ffe23122c10 INFO: task syz.4.1549:12113 blocked for more than 188 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.1549 state:D stack:27064 pid:12113 tgid:12112 ppid:11890 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5258 [inline] __schedule+0x150e/0x5070 kernel/sched/core.c:6866 __schedule_loop kernel/sched/core.c:6948 [inline] schedule+0x165/0x360 kernel/sched/core.c:6963 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7020 rwsem_down_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1086 __down_read_common kernel/locking/rwsem.c:1261 [inline] __down_read kernel/locking/rwsem.c:1274 [inline] down_read+0x99/0x2e0 kernel/locking/rwsem.c:1539 inode_lock_shared include/linux/fs.h:1043 [inline] blkdev_read_iter+0x2f8/0x440 block/fops.c:855 do_iter_readv_writev+0x623/0x8c0 fs/read_write.c:-1 vfs_readv+0x253/0x850 fs/read_write.c:1018 do_preadv fs/read_write.c:1132 [inline] __do_sys_preadv fs/read_write.c:1179 [inline] __se_sys_preadv fs/read_write.c:1174 [inline] __x64_sys_preadv+0x197/0x2a0 fs/read_write.c:1174 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd7ba78f749 RSP: 002b:00007fd7bb55f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 00007fd7ba9e5fa0 RCX: 00007fd7ba78f749 RDX: 0000000000000001 RSI: 0000200000000000 RDI: 0000000000000003 RBP: 00007fd7ba813f91 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000fffffffc R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd7ba9e6038 R14: 00007fd7ba9e5fa0 R15: 00007ffce25c1d68 Showing all locks held in the system: 4 locks held by kworker/0:0/9: #0: ffff8880b863ab18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:639 #1: ffff8880b8624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 #2: ffff8880b8628258 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1781 [inline] #2: ffff8880b8628258 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x5e2/0xc30 kernel/time/hrtimer.c:1841 #3: ffffffff99d3d508 (&____s->seqcount#2){----}-{0:0}, at: ktime_get+0x45/0x200 kernel/time/timekeeping.c:824 3 locks held by kworker/1:0/24: #0: ffff88813fe55948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254 #1: ffffc900001e7b80 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255 #2: ffffffff8f72c588 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 1 lock held by khungtaskd/31: #0: ffffffff8e33f2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e33f2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e33f2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:2/36: 3 locks held by kworker/u8:3/37: #0: ffff88814cf53948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254 #1: ffffc90000ad7b80 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255 #2: ffffffff8f72c588 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f72c588 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4734 3 locks held by kworker/0:2/890: #0: ffff88813fe56948 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254 #1: ffffc90003af7b80 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255 #2: ffffffff8f72c588 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0xa1/0xf00 net/wireless/reg.c:2453 4 locks held by kworker/u8:10/3083: 5 locks held by kworker/u8:11/3426: 1 lock held by klogd/5191: 2 locks held by getty/5587: #0: ffff88814d2d70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460 drivers/tty/n_tty.c:2211 2 locks held by udevd/5840: 2 locks held by syz.7.1052/10116: #0: ffff888023d59328 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #0: ffff888023d59328 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: blkdev_fallocate+0x260/0x530 block/fops.c:908 #1: ffff888023d594c8 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock include/linux/fs.h:1083 [inline] #1: ffff888023d594c8 (mapping.invalidate_lock){++++}-{4:4}, at: blkdev_fallocate+0x290/0x530 block/fops.c:909 2 locks held by syz.9.1385/11413: #0: ffff88805a65d848 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #0: ffff88805a65d848 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release+0x89/0x250 net/socket.c:665 #1: ffff8880300d0260 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1700 [inline] #1: ffff8880300d0260 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: pptp_release+0x52/0x310 drivers/net/ppp/pptp.c:513 1 lock held by syz.1.1481/11739: #0: ffff888023d594c8 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1093 [inline] #0: ffff888023d594c8 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x37a/0xe50 mm/readahead.c:494 1 lock held by syz.6.1484/11747: #0: ffff888023d594c8 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1093 [inline] #0: ffff888023d594c8 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x37a/0xe50 mm/readahead.c:494 1 lock held by syz.4.1549/12113: #0: ffff888023d59328 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1043 [inline] #0: ffff888023d59328 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: blkdev_read_iter+0x2f8/0x440 block/fops.c:855 3 locks held by kworker/u8:6/12306: #0: ffff88813fe69948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254 #1: ffffc9000cc4fb80 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255 #2: ffffffff8f72c588 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 1 lock held by syz-executor/12439: 1 lock held by syz.8.1771/13285: #0: ffff888023d594c8 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1093 [inline] #0: ffff888023d594c8 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x37a/0xe50 mm/readahead.c:494 1 lock held by syz-executor/13538: #0: ffffffff8e344e38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #0: ffffffff8e344e38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:956 1 lock held by syz.3.1878/14040: 1 lock held by dhcpcd/14046: #0: ffff888039d90260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1700 [inline] #0: ffff888039d90260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xd30 net/packet/af_packet.c:3197 1 lock held by dhcpcd/14047: #0: ffff88803b79e260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1700 [inline] #0: ffff88803b79e260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xd30 net/packet/af_packet.c:3197 1 lock held by dhcpcd/14048: #0: ffff88803b79c260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1700 [inline] #0: ffff88803b79c260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xd30 net/packet/af_packet.c:3197 ============================================= 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 10/25/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [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:363 [inline] watchdog+0xe40/0xe90 kernel/hung_task.c:557 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 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: 2994 Comm: kworker/u8:9 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:hlock_class kernel/locking/lockdep.c:234 [inline] RIP: 0010:__lock_acquire+0xa55/0x2cf0 kernel/locking/lockdep.c:5234 Code: c7 c6 7e c4 b8 8d 67 48 0f b9 3a 90 31 c0 48 83 78 40 00 0f 84 5f 1d 00 00 41 8b 45 20 25 ff 1f 00 00 48 0f a3 05 9b 48 2d 12 <73> 10 48 69 c0 c8 00 00 00 48 8d 80 b0 03 6d 93 eb 32 83 3d 62 d8 RSP: 0018:ffffc9000b5ef190 EFLAGS: 00000003 RAX: 0000000000000007 RBX: 00000000326678ea RCX: 00000000fe008f03 RDX: 000000001ad5365c RSI: 00000000f8948429 RDI: ffff88802feebd00 RBP: 27490ac900000000 R08: ffffffff81746f85 R09: ffffffff8e33f2e0 R10: ffffc9000b5ef4f8 R11: fffff520016bdea1 R12: ffff88802feec8d0 R13: ffff88802feec8d0 R14: ffff88802feebd00 R15: 0000000000000004 FS: 0000000000000000(0000) GS:ffff8881259dc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005576f0ff0e40 CR3: 000000000e138000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x117/0x340 kernel/locking/lockdep.c:5868 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0xc2/0x23d0 arch/x86/kernel/unwind_orc.c:495 __unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:773 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 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:5267 [inline] kmem_cache_alloc_node_noprof+0x43c/0x720 mm/slub.c:5319 __alloc_skb+0x255/0x430 net/core/skbuff.c:679 alloc_skb include/linux/skbuff.h:1383 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:819 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:876 [inline] nsim_dev_trap_report_work+0x29a/0xb80 drivers/net/netdevsim/dev.c:922 process_one_work+0x93a/0x15a0 kernel/workqueue.c:3279 process_scheduled_works kernel/workqueue.c:3362 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3443 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246