rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P1309/1:b..l P29415/2:b..l P8996/1:b..l rcu: (detected by 1, t=10502 jiffies, g=181701, q=148 ncpus=2) task:syz-executor state:R running task stack:21456 pid:8996 ppid:8986 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6867 preempt_schedule+0xc0/0xd0 kernel/sched/core.c:6891 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3a/0x40 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] copy_pte_range mm/memory.c:1107 [inline] copy_pmd_range mm/memory.c:1168 [inline] copy_pud_range mm/memory.c:1205 [inline] copy_p4d_range mm/memory.c:1229 [inline] copy_page_range+0x2ba0/0x3670 mm/memory.c:1323 dup_mmap kernel/fork.c:764 [inline] dup_mm kernel/fork.c:1692 [inline] copy_mm+0x11cb/0x1d50 kernel/fork.c:1741 copy_process+0x16f7/0x3d80 kernel/fork.c:2506 kernel_clone+0x24b/0x8a0 kernel/fork.c:2914 __do_sys_clone kernel/fork.c:3057 [inline] __se_sys_clone kernel/fork.c:3041 [inline] __x64_sys_clone+0x1b7/0x230 kernel/fork.c:3041 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f7a18bc3a12 RSP: 002b:00007fffb8fb10b0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007fffb8fb10b0 RCX: 00007f7a18bc3a12 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007fffb8fb123c R08: 0000000000000000 R09: 0000000000000001 R10: 000055558cbb27d0 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000000927c0 R14: 00000000001b3500 R15: 00007fffb8fb1290 task:dhcpcd-run-hook state:R running task stack:24040 pid:29415 ppid:5432 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 preempt_schedule_irq+0xbf/0x150 kernel/sched/core.c:7010 irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:692 RIP: 0010:__prepend_path fs/d_path.c:111 [inline] RIP: 0010:prepend_path+0x4b2/0x960 fs/d_path.c:172 Code: 8d 44 89 f1 80 e1 07 38 c1 7c d3 4c 89 f7 e8 35 75 e2 ff eb c9 4c 8b 74 24 48 49 8d 7e 10 48 89 f8 48 c1 e8 03 42 80 3c 28 00 <74> 05 e8 d7 74 e2 ff 49 8b 5e 10 49 39 de 4c 8b 64 24 08 0f 84 62 RSP: 0018:ffffc900033b7978 EFLAGS: 00000246 RAX: 1ffff110036c8612 RBX: ffff88802c96ad38 RCX: ffff888027455a00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88801b643090 RBP: ffffc900033b7a48 R08: ffffffff911bf53f R09: 1ffffffff2237ea7 R10: dffffc0000000000 R11: fffffbfff2237ea8 R12: ffff88801b6430a0 R13: dffffc0000000000 R14: ffff88801b643080 R15: ffff88802c96ad38 d_absolute_path+0xa2/0x140 fs/d_path.c:234 tomoyo_get_absolute_path security/tomoyo/realpath.c:101 [inline] tomoyo_realpath_from_path+0x2d9/0x5d0 security/tomoyo/realpath.c:271 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x282/0x560 security/tomoyo/file.c:822 security_inode_getattr+0xd3/0x120 security/security.c:2153 vfs_getattr fs/stat.c:173 [inline] vfs_fstat fs/stat.c:198 [inline] __do_sys_newfstat fs/stat.c:473 [inline] __se_sys_newfstat fs/stat.c:470 [inline] __x64_sys_newfstat+0x12c/0x250 fs/stat.c:470 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f4f2a7a1e87 RSP: 002b:00007ffc2f06f638 EFLAGS: 00000246 ORIG_RAX: 0000000000000005 RAX: ffffffffffffffda RBX: 00007f4f2a77e0c0 RCX: 00007f4f2a7a1e87 RDX: 0000000000000003 RSI: 00007ffc2f06f6d0 RDI: 0000000000000003 RBP: 00007ffc2f06f790 R08: 00007f4f2a77fa90 R09: 00007f4f2a77e0c0 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ffc2f06f830 R15: 0000000000000000 task:kworker/u4:8 state:R running task stack:21448 pid:1309 ppid:2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 preempt_schedule_irq+0xbf/0x150 kernel/sched/core.c:7010 irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:check_region_inline mm/kasan/generic.c:169 [inline] RIP: 0010:kasan_check_range+0x10/0x290 mm/kasan/generic.c:187 Code: c0 c3 0f 0b b8 ea ff ff ff c3 0f 0b b8 ea ff ff ff c3 cc cc cc cc cc cc cc cc 66 0f 1f 00 b0 01 48 85 f6 0f 84 b4 01 00 00 55 <41> 57 41 56 41 55 41 54 53 4c 8d 04 37 49 39 f8 0f 82 13 02 00 00 RSP: 0018:ffffc90004ecfa30 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff81682227 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8e8add28 RBP: ffffc90004ecfb48 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff1d15ba6 R12: 1ffff920009d9f54 R13: ffffffff8d131fe0 R14: 0000000000000001 R15: dffffc0000000000 instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] cpumask_test_cpu include/linux/cpumask.h:504 [inline] cpu_online include/linux/cpumask.h:1082 [inline] trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0xb7/0x420 kernel/locking/lockdep.c:5725 rcu_lock_acquire include/linux/rcupdate.h:334 [inline] rcu_read_lock include/linux/rcupdate.h:786 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0xef/0x610 net/batman-adv/network-coding.c:719 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 rcu: rcu_preempt kthread starved for 10383 jiffies! g181701 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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:27656 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x313/0x1590 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 RIP: 0010:pv_native_safe_halt+0xf/0x10 arch/x86/kernel/paravirt.c:148 Code: e7 22 02 c3 cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d 83 f1 43 00 fb f4 66 0f 1f 00 55 41 57 41 56 41 54 53 50 8b 2f eb 2e 41 89 de 80 RSP: 0018:ffffc90000187de0 EFLAGS: 000002c2 RAX: a756f83776bfb500 RBX: ffffffff8162a490 RCX: a756f83776bfb500 RDX: 0000000000000001 RSI: ffffffff8acac900 RDI: ffffffff8b1c81e0 RBP: ffffc90000187f20 R08: ffff8880b8f36b2b R09: 1ffff110171e6d65 R10: dffffc0000000000 R11: ffffed10171e6d66 R12: 1ffff1100384b780 R13: 1ffff92000030fc8 R14: 0000000000000001 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb0cfeecbdb CR3: 0000000076136000 CR4: 00000000003506e0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:753 default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97 cpuidle_idle_call kernel/sched/idle.c:170 [inline] do_idle+0x1f0/0x4e0 kernel/sched/idle.c:282 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:380 start_secondary+0xee/0xf0 arch/x86/kernel/smpboot.c:323 secondary_startup_64_no_verify+0x179/0x17b