rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=154c/1/0x4000000000000000 softirq=45301/45302 fqs=24 rcu: (detected by 1, t=10502 jiffies, g=41773, q=578 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5853 Comm: syz-executor Not tainted 6.12.0-rc5-syzkaller-00322-gb9021de3ec2f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:__kasan_check_read+0x0/0x20 mm/kasan/shadow.c:30 Code: 8e 4c 89 fe e8 61 7d c5 09 31 db eb d0 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 89 f6 48 8b 0c 24 31 d2 e9 6f e6 ff ff 66 2e 0f 1f 84 RSP: 0018:ffffc90000007b78 EFLAGS: 00000056 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000010000 RSI: 0000000000000008 RDI: ffffffff901d09a8 RBP: ffffc90000007cb0 R08: ffffffff818233d7 R09: 1ffffffff203a135 R10: dffffc0000000000 R11: fffffbfff203a136 R12: 1ffff92000000f7c R13: ffffffff81823447 R14: ffffc90000007ce0 R15: dffffc0000000000 FS: 0000555575739500(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fab58e04f98 CR3: 0000000063c56000 CR4: 0000000000350ef0 Call Trace: 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:570 [inline] cpu_online include/linux/cpumask.h:1117 [inline] trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0xb0/0xa30 kernel/locking/lockdep.c:5836 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline] _raw_spin_unlock_irqrestore+0x79/0x140 kernel/locking/spinlock.c:194 __run_hrtimer kernel/time/hrtimer.c:1687 [inline] __hrtimer_run_queues+0x477/0xd50 kernel/time/hrtimer.c:1755 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1817 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x112/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:rcu_lockdep_current_cpu_online+0x39/0x120 kernel/rcu/tree.c:4774 Code: 7e b0 01 f7 c1 00 00 f0 00 0f 85 d5 00 00 00 83 3d db e6 a1 0e 00 0f 84 c8 00 00 00 65 ff 05 f6 b3 88 7e e8 49 21 4c 0a 89 c3 <83> f8 08 0f 83 c6 00 00 00 49 be 00 00 00 00 00 fc ff df 48 8d 1c RSP: 0018:ffffc90002f5f1a0 EFLAGS: 00000286 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000080000002 RDX: 0000000000000000 RSI: ffffffff8c610840 RDI: ffffffff8c610800 RBP: 00000000000001a0 R08: ffffffff820b684e R09: 1ffffffff2859b00 R10: dffffc0000000000 R11: fffffbfff2859b01 R12: 000000000006e588 R13: 0000000000000001 R14: ffffffff820b6780 R15: ffff88801c380000 rcu_read_lock_held_common kernel/rcu/update.c:113 [inline] rcu_read_lock_held+0x1e/0x50 kernel/rcu/update.c:349 lookup_page_ext mm/page_ext.c:254 [inline] page_ext_get+0x192/0x2a0 mm/page_ext.c:526 page_table_check_set+0x4f/0x540 mm/page_table_check.c:114 __page_table_check_ptes_set+0x30f/0x410 mm/page_table_check.c:225 page_table_check_ptes_set include/linux/page_table_check.h:74 [inline] set_ptes include/linux/pgtable.h:267 [inline] __copy_present_ptes mm/memory.c:969 [inline] copy_present_ptes mm/memory.c:1052 [inline] copy_pte_range mm/memory.c:1167 [inline] copy_pmd_range+0x4773/0x85f0 mm/memory.c:1255 copy_pud_range mm/memory.c:1292 [inline] copy_p4d_range mm/memory.c:1316 [inline] copy_page_range+0x99f/0xe90 mm/memory.c:1414 dup_mmap kernel/fork.c:746 [inline] dup_mm kernel/fork.c:1675 [inline] copy_mm+0x1117/0x1e80 kernel/fork.c:1724 copy_process+0x1845/0x3d50 kernel/fork.c:2374 kernel_clone+0x226/0x8f0 kernel/fork.c:2786 __do_sys_clone kernel/fork.c:2929 [inline] __se_sys_clone kernel/fork.c:2913 [inline] __x64_sys_clone+0x258/0x2a0 kernel/fork.c:2913 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f08f4974f93 Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00 RSP: 002b:00007ffd6b94e558 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f08f4974f93 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 00005555757397d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000503e6 R14: 00000000000503c1 R15: 00007ffd6b94e6e0 rcu: rcu_preempt kthread starved for 10454 jiffies! g41773 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:25200 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x184f/0x4c30 kernel/sched/core.c:6690 __schedule_loop kernel/sched/core.c:6767 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6782 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2615 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 12916 Comm: syz.0.2475 Not tainted 6.12.0-rc5-syzkaller-00322-gb9021de3ec2f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:get_current arch/x86/include/asm/current.h:49 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216 Code: 8b 3d b4 38 9d 0c 48 89 de 5b e9 73 d6 5d 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0c 25 c0 d7 03 00 65 8b 15 10 fe 6e 7e 81 e2 00 01 ff 00 RSP: 0018:ffffc9001b1bf718 EFLAGS: 00000202 RAX: ffffffff8188ea8b RBX: 1ffff110170c8ca1 RCX: 0000000000040000 RDX: ffffc9000cb79000 RSI: 000000000003ffff RDI: 0000000000040000 RBP: ffffc9001b1bf908 R08: ffffffff8188ea5a R09: 1ffffffff2859b13 R10: dffffc0000000000 R11: fffffbfff2859b14 R12: dffffc0000000000 R13: ffff8880b8646508 R14: ffff8880b873fc80 R15: 0000000000000000 FS: 00007fab58de46c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fab57f60f40 CR3: 000000007f26e000 CR4: 0000000000350ef0 Call Trace: csd_lock_wait kernel/smp.c:340 [inline] smp_call_function_many_cond+0x1a0b/0x2ca0 kernel/smp.c:884 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1051 kill_bdev block/bdev.c:90 [inline] set_blocksize+0x2e2/0x360 block/bdev.c:173 sb_set_blocksize+0x47/0xf0 block/bdev.c:182 ext4_load_super fs/ext4/super.c:5061 [inline] __ext4_fill_super fs/ext4/super.c:5213 [inline] ext4_fill_super+0x12f0/0x6e60 fs/ext4/super.c:5686 get_tree_bdev_flags+0x48e/0x5c0 fs/super.c:1636 vfs_get_tree+0x92/0x2b0 fs/super.c:1814 do_new_mount+0x2be/0xb40 fs/namespace.c:3507 do_mount fs/namespace.c:3847 [inline] __do_sys_mount fs/namespace.c:4057 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4034 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fab57f7feba Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fab58de3e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fab58de3ef0 RCX: 00007fab57f7feba RDX: 00000000200000c0 RSI: 0000000020000000 RDI: 00007fab58de3eb0 RBP: 00000000200000c0 R08: 00007fab58de3ef0 R09: 0000000000804810 R10: 0000000000804810 R11: 0000000000000246 R12: 0000000020000000 R13: 00007fab58de3eb0 R14: 000000000000076b R15: 00000000200002c0