rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P11449/1:b..l rcu: (detected by 0, t=10502 jiffies, g=60805, q=500 ncpus=2) task:syz.6.1176 state:R running task stack:19736 pid:11449 tgid:11446 ppid:10425 task_flags:0x440140 flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256 irqentry_exit+0x6f/0x90 kernel/entry/common.c:211 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:kasan_check_range+0x1da/0x2c0 mm/kasan/generic.c:200 Code: 07 4d 85 e4 49 0f 49 dc 48 83 e3 f8 49 29 dc 74 12 41 80 3b 00 0f 85 b8 00 00 00 49 ff c3 49 ff cc 75 ee 5b 41 5c 41 5d 41 5e <41> 5f 5d e9 f9 9b ea fe cc 45 84 ff 75 63 41 f7 c7 00 ff 00 00 75 RSP: 0018:ffffc90004bed9e0 EFLAGS: 00000256 RAX: 1ffff9200097db01 RBX: 0000000000000010 RCX: ffffffff81739918 RDX: 0000000000000001 RSI: 0000000000000010 RDI: ffffc90004bedb38 RBP: 0000000000000000 R08: ffffc90004bedb47 R09: 1ffff9200097db68 R10: dffffc0000000000 R11: fffff5200097db69 R12: ffffc90004beec80 R13: ffffc90004bedb38 R14: ffffc90004bedb38 R15: 1ffff9200097db67 __asan_memset+0x22/0x50 mm/kasan/shadow.c:84 unwind_next_frame+0xc98/0x2390 arch/x86/kernel/unwind_orc.c:592 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:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 __kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2539 [inline] slab_free mm/slub.c:6630 [inline] kmem_cache_free+0x19b/0x690 mm/slub.c:6740 nilfs_btree_lookup_contig+0xafa/0xc20 fs/nilfs2/btree.c:782 nilfs_bmap_lookup_contig+0x91/0x160 fs/nilfs2/bmap.c:97 nilfs_get_block+0x1fb/0x8f0 fs/nilfs2/inode.c:84 do_mpage_readpage+0x822/0x1990 fs/mpage.c:222 mpage_readahead+0x3b0/0x790 fs/mpage.c:371 read_pages+0x17a/0x580 mm/readahead.c:163 page_cache_ra_unbounded+0x75e/0x9a0 mm/readahead.c:302 filemap_readahead mm/filemap.c:2606 [inline] filemap_get_pages+0x7fd/0x1de0 mm/filemap.c:2652 filemap_read+0x3f6/0x11a0 mm/filemap.c:2748 __kernel_read+0x4cf/0x960 fs/read_write.c:530 integrity_kernel_read+0x89/0xd0 security/integrity/iint.c:28 ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:480 [inline] ima_calc_file_shash security/integrity/ima/ima_crypto.c:511 [inline] ima_calc_file_hash+0x85e/0x16f0 security/integrity/ima/ima_crypto.c:568 ima_collect_measurement+0x428/0x8f0 security/integrity/ima/ima_api.c:293 process_measurement+0x1121/0x1a40 security/integrity/ima/ima_main.c:405 ima_file_check+0xd7/0x120 security/integrity/ima/ima_main.c:633 security_file_post_open+0xbb/0x290 security/security.c:3199 do_open fs/namei.c:3977 [inline] path_openat+0x2f26/0x3830 fs/namei.c:4134 do_filp_open+0x1fa/0x410 fs/namei.c:4161 do_sys_openat2+0x121/0x1c0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1463 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0f3418f6c9 RSP: 002b:00007f0f35050038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f0f343e6090 RCX: 00007f0f3418f6c9 RDX: 0000000000143142 RSI: 0000200000000400 RDI: ffffffffffffff9c RBP: 00007f0f34211f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000040 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0f343e6128 R14: 00007f0f343e6090 R15: 00007ffef0673758 rcu: rcu_preempt kthread starved for 10309 jiffies! g60805 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:26976 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 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+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: 5e 03 ca f5 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 f3 f1 21 00 f3 0f 1e fa fb f4 33 03 ca f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6 RAX: 852ac8b2418aa000 RBX: ffffffff81967bf7 RCX: 852ac8b2418aa000 RDX: 0000000000000001 RSI: ffffffff8d70d481 RDI: ffffffff8bbf0760 RBP: ffffc90000197f10 R08: ffff8880b8932fdb R09: 1ffff110171265fb R10: dffffc0000000000 R11: ffffed10171265fc R12: ffffffff8f7cdc70 R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff110038d9b58 FS: 0000000000000000(0000) GS:ffff88812623d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff8907bc000 CR3: 0000000030477000 CR4: 0000000000350ef0 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:190 [inline] do_idle+0x1e7/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x147