rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7660/1:b..l rcu: (detected by 0, t=10502 jiffies, g=20193, q=6867 ncpus=2) task:syz.0.388 state:R running task stack:25608 pid:7660 tgid:7658 ppid:5834 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x16aa/0x4c90 kernel/sched/core.c:6786 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7109 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707 RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5875 Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 6b 55 fe 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: e57e:ffffc9000b326da8 EFLAGS: ffff888024ba3c00 ORIG_RAX: 0000000000000246 RAX: 0000000080000000 RBX: 0000000000000000 RCX: ffff888024ba3c00 RDX: ffffc9000b326da8 RSI: ffffffff81a72aa5 RDI: 1ffff92001664da0 ================================================================== BUG: KASAN: stack-out-of-bounds in __show_regs+0x170/0x620 arch/x86/kernel/process_64.c:88 Read of size 8 at addr ffffc9000b326c38 by task swapper/0/0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.16.0-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 __show_regs+0x170/0x620 arch/x86/kernel/process_64.c:88 show_regs_if_on_stack arch/x86/kernel/dumpstack.c:165 [inline] show_trace_log_lvl+0x423/0x550 arch/x86/kernel/dumpstack.c:298 sched_show_task+0x49d/0x630 kernel/sched/core.c:7754 rcu_print_detail_task_stall_rnp kernel/rcu/tree_stall.h:256 [inline] print_other_cpu_stall+0xfa6/0x1370 kernel/rcu/tree_stall.h:645 check_cpu_stall kernel/rcu/tree_stall.h:821 [inline] rcu_pending kernel/rcu/tree.c:3642 [inline] rcu_sched_clock_irq+0x9d1/0x1090 kernel/rcu/tree.c:2677 update_process_times+0x23c/0x2f0 kernel/time/timer.c:2473 tick_sched_handle kernel/time/tick-sched.c:276 [inline] tick_nohz_handler+0x39a/0x520 kernel/time/tick-sched.c:297 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x4dd/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: 53 de 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d d3 ad 21 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8de07d80 EFLAGS: 000002c2 RAX: 318aeea7de08bf00 RBX: ffffffff81976918 RCX: 318aeea7de08bf00 RDX: 0000000000000001 RSI: ffffffff8d982fba RDI: ffffffff8be1ba40 RBP: ffffffff8de07ea8 R08: ffff8880b8632f5b R09: 1ffff110170c65eb R10: dffffc0000000000 R11: ffffed10170c65ec R12: ffffffff8fa0b3f0 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1bd2a50 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:749 default_idle_call+0x74/0xb0 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x1e8/0x510 kernel/sched/idle.c:325 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:423 rest_init+0x2de/0x300 init/main.c:745 start_kernel+0x47d/0x500 init/main.c:1102 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:307 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:288 common_startup_64+0x13e/0x147 The buggy address belongs to a 8-page vmalloc region starting at 0xffffc9000b320000 allocated at copy_process+0x544/0x3b80 kernel/fork.c:1999 The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888077822000 pfn:0x77822 memcg:ffff888024341382 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000 raw: ffff888077822000 0000000000000000 00000001ffffffff ffff888024341382 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x2dc2(GFP_KERNEL|__GFP_HIGHMEM|__GFP_ZERO|__GFP_NOWARN), pid 7606, tgid 7606 (syz.0.378), ts 314430712931, free_ts 313978662106 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1704 prep_new_page mm/page_alloc.c:1712 [inline] get_page_from_freelist+0x21d5/0x22b0 mm/page_alloc.c:3669 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419 alloc_frozen_pages_noprof mm/mempolicy.c:2490 [inline] alloc_pages_noprof+0xa9/0x190 mm/mempolicy.c:2510 vm_area_alloc_pages mm/vmalloc.c:3642 [inline] __vmalloc_area_node mm/vmalloc.c:3720 [inline] __vmalloc_node_range_noprof+0x97d/0x12f0 mm/vmalloc.c:3893 __vmalloc_node_noprof+0xc2/0x110 mm/vmalloc.c:3956 alloc_thread_stack_node kernel/fork.c:317 [inline] dup_task_struct+0x3e7/0x860 kernel/fork.c:877 copy_process+0x544/0x3b80 kernel/fork.c:1999 kernel_clone+0x224/0x7f0 kernel/fork.c:2599 __do_sys_clone3 kernel/fork.c:2903 [inline] __se_sys_clone3+0x256/0x2d0 kernel/fork.c:2882 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 15 tgid 15 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0xc65/0xe60 mm/page_alloc.c:2706 pagetable_free include/linux/mm.h:2884 [inline] pagetable_dtor_free include/linux/mm.h:2982 [inline] __tlb_remove_table+0x2d2/0x3b0 include/asm-generic/tlb.h:220 __tlb_remove_table_free mm/mmu_gather.c:227 [inline] tlb_remove_table_rcu+0x85/0x100 mm/mmu_gather.c:290 rcu_do_batch kernel/rcu/tree.c:2576 [inline] rcu_core+0xca5/0x1710 kernel/rcu/tree.c:2832 handle_softirqs+0x283/0x870 kernel/softirq.c:579 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:968 smpboot_thread_fn+0x53f/0xa60 kernel/smpboot.c:164 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffffc9000b326b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffffc9000b326b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffffc9000b326c00: f1 f1 f1 f1 00 f2 f2 f2 00 f3 f3 f3 00 00 00 00 ^ ffffc9000b326c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffffc9000b326d00: f1 f1 f1 f1 00 f2 f2 f2 00 f3 f3 f3 00 00 00 00 ==================================================================