INFO: task kworker/u8:7:29238 blocked for more than 123 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:7 state:D stack:0 pid:29238 tgid:29238 ppid:2 flags:0x00004000 Workqueue: events_unbound linkwatch_event Call Trace: context_switch kernel/sched/core.c:5945 [inline] __schedule+0x1322/0x1df0 kernel/sched/core.c:7791 __schedule_loop kernel/sched/core.c:7872 [inline] schedule+0xc6/0x240 kernel/sched/core.c:7887 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7944 __mutex_lock_common kernel/locking/mutex.c:707 [inline] __mutex_lock+0x81e/0x1b50 kernel/locking/mutex.c:803 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134 mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:285 rtnl_lock+0x19/0x20 net/core/rtnetlink.c:79 linkwatch_event+0x12/0x60 net/core/link_watch.c:285 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0x7d5/0x1020 kernel/workqueue.c:3319 worker_thread+0xc58/0x1250 kernel/workqueue.c:3400 kthread+0x2c7/0x370 kernel/kthread.c:389 ret_from_fork+0x64/0xa0 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 INFO: task kworker/u8:22:29253 blocked for more than 125 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:22 state:D stack:0 pid:29253 tgid:29253 ppid:2 flags:0x00004000 Workqueue: ipv6_addrconf addrconf_verify_work Call Trace: context_switch kernel/sched/core.c:5945 [inline] __schedule+0x1322/0x1df0 kernel/sched/core.c:7791 __schedule_loop kernel/sched/core.c:7872 [inline] schedule+0xc6/0x240 kernel/sched/core.c:7887 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7944 __mutex_lock_common kernel/locking/mutex.c:707 [inline] __mutex_lock+0x81e/0x1b50 kernel/locking/mutex.c:803 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134 mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:285 rtnl_lock+0x19/0x20 net/core/rtnetlink.c:79 addrconf_verify_work+0x1d/0x50 net/ipv6/addrconf.c:4775 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0x7d5/0x1020 kernel/workqueue.c:3319 worker_thread+0xc58/0x1250 kernel/workqueue.c:3400 kthread+0x2c7/0x370 kernel/kthread.c:389 ret_from_fork+0x64/0xa0 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 3aa8e93a75ec4fb080c21ea51d8727149e6cfac5 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:94 dump_stack_lvl+0x10c/0x190 lib/dump_stack.c:120 dump_stack+0x19/0x20 lib/dump_stack.c:129 nmi_cpu_backtrace+0x2bf/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:267 [inline] watchdog+0xd8f/0xed0 kernel/hung_task.c:423 kthread+0x2c7/0x370 kernel/kthread.c:389 ret_from_fork+0x64/0xa0 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 2047 Comm: syz-executor Not tainted syzkaller #0 3aa8e93a75ec4fb080c21ea51d8727149e6cfac5 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:nr_pcp_high mm/page_alloc.c:2765 [inline] RIP: 0010:free_unref_page_commit+0x5e4/0xea0 mm/page_alloc.c:2813 Code: 06 00 48 ba 00 00 00 00 00 fc ff df 49 f7 04 24 04 00 00 00 48 8b 75 b0 4c 89 eb 0f 85 98 00 00 00 4c 8b 4d b8 41 0f b6 04 11 <84> c0 4c 8b 45 c8 44 8b 65 a8 4c 8b 55 c0 44 8b 5d d4 4c 8b 6d 98 RSP: 0018:ffffc90002b9f278 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff8881f6e7229a RCX: ffffffff81d529b4 RDX: dffffc0000000000 RSI: ffff8881f6e72284 RDI: ffffffff87c2cef8 RBP: ffffc90002b9f2f0 R08: ffffffff87c2ceff R09: 1ffff1103edce450 R10: dffffc0000000000 R11: fffffbfff0f859e0 R12: ffffffff87c2cef8 R13: ffff8881f6e7229a R14: 0000000000000fd8 R15: 1ffff1103edce451 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055e5d251db98 CR3: 00000000072a8000 CR4: 00000000003526b0 Call Trace: free_unref_folios+0x12d3/0x1680 mm/page_alloc.c:2985 folios_put_refs+0x4c9/0x5c0 mm/swap.c:1038 free_pages_and_swap_cache+0x272/0x460 mm/swap_state.c:333 __tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline] tlb_batch_pages_flush mm/mmu_gather.c:149 [inline] tlb_flush_mmu_free mm/mmu_gather.c:366 [inline] tlb_flush_mmu+0x7ce/0xaf0 mm/mmu_gather.c:373 tlb_finish_mmu+0xcf/0x1d0 mm/mmu_gather.c:465 exit_mmap+0x405/0xb60 mm/mmap.c:1976 __mmput+0x93/0x320 kernel/fork.c:1349 mmput+0x55/0x170 kernel/fork.c:1372 exit_mm kernel/exit.c:574 [inline] do_exit+0x918/0x2630 kernel/exit.c:940 do_group_exit+0x22a/0x300 kernel/exit.c:1095 get_signal+0x139d/0x14f0 kernel/signal.c:2933 arch_do_signal_or_restart+0x96/0x720 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x58/0xb0 kernel/entry/common.c:218 do_syscall_64+0x64/0xf0 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fbb7f590a23 Code: Unable to access opcode bytes at 0x7fbb7f5909f9. RSP: 002b:00007fff0dfcf588 EFLAGS: 00000202 ORIG_RAX: 000000000000002c RAX: 000000000000002c RBX: 00007fbb802f4620 RCX: 00007fbb7f590a23 RDX: 000000000000002c RSI: 00007fbb802f4670 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00007fff0dfcf5a4 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003 R13: 0000000000000000 R14: 00007fbb802f4670 R15: 0000000000000000