rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P10263/1:b..l P10327/2:b..l rcu: (detected by 0, t=10502 jiffies, g=41629, q=359 ncpus=2) task:syz.6.792 state:R running task stack:23624 pid:10327 tgid:10326 ppid:7564 task_flags:0x400140 flags:0x00080802 Call Trace: context_switch kernel/sched/core.c:5258 [inline] __schedule+0x150e/0x5070 kernel/sched/core.c:6866 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7193 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:unwind_next_frame+0x18e7/0x23d0 arch/x86/kernel/unwind_orc.c:679 Code: 24 48 01 c6 4c 89 f7 48 89 da e8 84 0d 00 00 84 c0 0f 84 47 01 00 00 48 bd 00 00 00 00 00 fc ff df 48 8b 44 24 20 0f b6 04 28 <84> c0 0f 85 17 08 00 00 b3 01 8b 84 24 8c 00 00 00 41 39 06 4c 8b RSP: 0018:ffffc9000d94f058 EFLAGS: 00000202 RAX: 0000000000000000 RBX: ffffffff9044d1ce RCX: 0000000000000001 RDX: ffffc9000d94f168 RSI: dffffc0000000000 RDI: ffffc9000d94f7b0 RBP: dffffc0000000000 R08: ffffc9000d94f7b0 R09: 0000000000000000 R10: ffffc9000d94f178 R11: fffff52001b29e31 R12: ffffc9000d94f178 R13: 1ffff92001b29e27 R14: ffffc9000d94f128 R15: 1ffffffff2089a3a arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 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 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x3e2/0x700 mm/slub.c:5780 kmalloc_noprof include/linux/slab.h:957 [inline] proc_self_get_link+0xe6/0x180 fs/proc/self.c:22 pick_link+0x785/0xfa0 fs/namei.c:2003 step_into_slowpath+0x53b/0x7d0 fs/namei.c:2066 step_into fs/namei.c:2091 [inline] walk_component fs/namei.c:2227 [inline] link_path_walk+0xd50/0x18d0 fs/namei.c:2589 path_lookupat+0xe4/0x8c0 fs/namei.c:2745 filename_lookup+0x212/0x570 fs/namei.c:2775 kern_path+0x35/0x50 fs/namei.c:2987 tomoyo_realpath_nofollow+0x8b/0x100 security/tomoyo/realpath.c:303 tomoyo_find_next_domain+0x251/0x1aa0 security/tomoyo/domain.c:730 tomoyo_bprm_check_security+0x11c/0x180 security/tomoyo/tomoyo.c:102 security_bprm_check+0x89/0x270 security/security.c:794 search_binary_handler fs/exec.c:1659 [inline] exec_binprm fs/exec.c:1701 [inline] bprm_execve+0x887/0x1400 fs/exec.c:1753 do_execveat_common+0x510/0x6a0 fs/exec.c:1859 do_execveat fs/exec.c:1944 [inline] __do_sys_execveat fs/exec.c:2018 [inline] __se_sys_execveat fs/exec.c:2012 [inline] __x64_sys_execveat+0xc4/0xe0 fs/exec.c:2012 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: 0033:0x7f0cbab8f749 RSP: 002b:00007f0cbb9c2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000142 RAX: ffffffffffffffda RBX: 00007f0cbade5fa0 RCX: 00007f0cbab8f749 RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000007 RBP: 00007f0cbac13f91 R08: 0000000000001000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0cbade6038 R14: 00007f0cbade5fa0 R15: 00007fff756b5408 task:syz.8.785 state:R running task stack:25400 pid:10263 tgid:10263 ppid:8265 task_flags:0x40044c flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5258 [inline] __schedule+0x150e/0x5070 kernel/sched/core.c:6866 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7050 preempt_schedule+0xae/0xc0 kernel/sched/core.c:7074 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] zap_pte_range mm/memory.c:1884 [inline] zap_pmd_range mm/memory.c:1946 [inline] zap_pud_range mm/memory.c:1975 [inline] zap_p4d_range mm/memory.c:1996 [inline] unmap_page_range+0x3c17/0x44e0 mm/memory.c:2017 unmap_single_vma mm/memory.c:2059 [inline] unmap_vmas+0x399/0x580 mm/memory.c:2101 exit_mmap+0x239/0xb10 mm/mmap.c:1277 __mmput+0x118/0x430 kernel/fork.c:1177 exit_mm+0x1da/0x2c0 kernel/exit.c:581 do_exit+0x850/0x25b0 kernel/exit.c:959 do_group_exit+0x21c/0x2d0 kernel/exit.c:1112 get_signal+0x1285/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2d0/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7d893c2005 RSP: 002b:00007ffffaa24b20 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: 0000000000000000 RBX: 00007f7d895e5fa0 RCX: 00007f7d893c2005 RDX: 00007ffffaa24b60 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f7d895e7da0 R08: 0000000000000000 R09: 3fffffffffffffff R10: 0000000000000000 R11: 0000000000000293 R12: 000000000005e318 R13: 00007f7d895e6180 R14: ffffffffffffffff R15: 00007ffffaa24ca0 rcu: rcu_preempt kthread starved for 10578 jiffies! g41629 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:27168 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 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_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 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 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: cc cc cc cc 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 33 9e 2a 00 f3 0f 1e fa fb f4 48 ee 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8de07d80 EFLAGS: 000002c6 RAX: 3540ba8d11c5fb00 RBX: ffffffff819786ba RCX: 3540ba8d11c5fb00 RDX: 0000000000000001 RSI: ffffffff8d997e54 RDI: ffffffff8be07960 RBP: ffffffff8de07ea8 R08: ffff8880b86336db R09: 1ffff110170c66db R10: dffffc0000000000 R11: ffffed10170c66dc R12: ffffffff8fa22f70 R13: 1ffffffff1bd29b8 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125c25000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c24f1cb CR3: 000000007a20c000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1ea/0x520 kernel/sched/idle.c:332 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430 rest_init+0x2de/0x300 init/main.c:758 start_kernel+0x3ac/0x400 init/main.c:1208 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147