rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=8ab4/1/0x4000000000000000 softirq=21974/21975 fqs=1
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P6970/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=19813, q=573 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 7015 Comm: syz.3.400 Not tainted 6.15.0-syzkaller-09113-g8477ab143069 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:mark_lock+0x0/0x190 kernel/locking/lockdep.c:4717
Code: 89 df 48 8b 2c 24 e9 b0 fd ff ff 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <55> 41 57 41 56 41 55 41 54 53 8b 46 20 89 c1 81 e1 00 00 03 00 83
RSP: 0018:ffffc90000a08aa8 EFLAGS: 00000006
RAX: 00000000000c4000 RBX: 0000000000000002 RCX: ffffffff93447370
RDX: 0000000000000008 RSI: ffff8880358ba940 RDI: ffff8880358b9e00
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff84c5b53b
R10: ffffc90000a08ca0 R11: fffff52000141196 R12: 0000000000000002
R13: 0000000000000002 R14: ffff8880358ba940 R15: 0000000000000000
FS:  00007f0e4ff916c0(0000) GS:ffff888125d65000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000110030 CR3: 0000000024f56000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 mark_usage kernel/locking/lockdep.c:4677 [inline]
 __lock_acquire+0x6a8/0xd20 kernel/locking/lockdep.c:5194
 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162
 debug_object_activate+0xbb/0x420 lib/debugobjects.c:818
 debug_hrtimer_activate kernel/time/hrtimer.c:445 [inline]
 debug_activate kernel/time/hrtimer.c:484 [inline]
 enqueue_hrtimer+0x30/0x3a0 kernel/time/hrtimer.c:1088
 __run_hrtimer kernel/time/hrtimer.c:1778 [inline]
 __hrtimer_run_queues+0x656/0xc60 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+0x10b/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
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194
Code: 74 05 e8 9b c1 61 f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> a3 c5 2a f6 65 8b 05 cc a5 35 07 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc900041775e0 EFLAGS: 00000206
RAX: 1c38c950f1ca7a00 RBX: 0000000000000a02 RCX: 1c38c950f1ca7a00
RDX: 0000000000000006 RSI: ffffffff8d96e646 RDI: 0000000000000001
RBP: ffffc90004177670 R08: ffffffff8fa0a8f7 R09: 1ffffffff1f4151e
R10: dffffc0000000000 R11: fffffbfff1f4151f R12: dffffc0000000000
R13: ffff8880241f0f80 R14: ffff8880241f0f40 R15: 1ffff9200082eebc
 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
 __wake_up_common_lock+0x190/0x1f0 kernel/sched/wait.c:108
 __unix_dgram_recvmsg+0x49f/0xde0 net/unix/af_unix.c:2529
 sock_recvmsg_nosec+0x183/0x1c0 net/socket.c:1017
 ____sys_recvmsg+0x3aa/0x460 net/socket.c:2784
 ___sys_recvmsg+0x1b5/0x510 net/socket.c:2828
 do_recvmmsg+0x307/0x770 net/socket.c:2923
 __sys_recvmmsg net/socket.c:2997 [inline]
 __do_sys_recvmmsg net/socket.c:3020 [inline]
 __se_sys_recvmmsg net/socket.c:3013 [inline]
 __x64_sys_recvmmsg+0x190/0x240 net/socket.c:3013
 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
RIP: 0033:0x7f0e4f18e969
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007f0e4ff91038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f0e4f3b6080 RCX: 00007f0e4f18e969
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007f0e4f210ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f0e4f3b6080 R15: 00007f0e4f4dfa28
 </TASK>
task:syz.0.387       state:R  running task     stack:24904 pid:6970  tgid:6967  ppid:5848   task_flags:0x400040 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5392 [inline]
 __schedule+0x16f5/0x4d00 kernel/sched/core.c:6781
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7104
 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:preempt_count kernel/rcu/tree.c:3987 [inline]
RIP: 0010:rcu_lockdep_current_cpu_online+0x6/0x120 kernel/rcu/tree.c:3991
Code: 03 89 df e9 4e ff ff ff 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 <41> 56 53 65 8b 0d b0 54 f4 10 b0 01 f7 c1 00 00 f0 00 0f 85 d5 00
RSP: 0018:ffffc9000b087170 EFLAGS: 00000202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 6a601fc3dd976400
RDX: 0000000000000000 RSI: ffffffff8be26560 RDI: ffffffff8be26520
RBP: ffffc9000b087208 R08: 0000000000000000 R09: ffffffff822aef18
R10: dffffc0000000000 R11: fffff940003dba29 R12: ffff888033d4ab40
R13: dffffc0000000000 R14: 1ffff92001610e30 R15: dffffc0000000000
 rcu_read_lock_held_common kernel/rcu/update.c:113 [inline]
 rcu_read_lock_sched_held+0x74/0x100 kernel/rcu/update.c:124
 task_css include/linux/cgroup.h:453 [inline]
 mem_cgroup_from_task+0x4d/0x120 mm/memcontrol.c:899
 get_mem_cgroup_from_mm+0xd6/0x2a0 mm/memcontrol.c:952
 __mem_cgroup_charge+0x15/0x80 mm/memcontrol.c:4606
 mem_cgroup_charge include/linux/memcontrol.h:642 [inline]
 folio_prealloc+0x51/0x180 mm/memory.c:1061
 wp_page_copy mm/memory.c:3478 [inline]
 do_wp_page+0x125e/0x57e0 mm/memory.c:3939
 handle_pte_fault mm/memory.c:6013 [inline]
 __handle_mm_fault+0x1144/0x55e0 mm/memory.c:6140
 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6309
 do_user_addr_fault+0x764/0x1390 arch/x86/mm/fault.c:1387
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0010:__put_user_nocheck_4+0x3/0x10 arch/x86/lib/putuser.S:104
Code: d9 0f 01 cb 89 01 31 c9 0f 01 ca c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 01 cb <89> 01 31 c9 0f 01 ca e9 01 32 03 00 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc9000b0878b8 EFLAGS: 00050202
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00002000003d9030
RDX: ffff88803153da00 RSI: 0000000000000002 RDI: 00000000ffffffff
RBP: ffffc9000b087a30 R08: ffffc9000b087667 R09: 1ffff92001610ecc
R10: dffffc0000000000 R11: fffff52001610ecd R12: 0000000000000002
R13: dffffc0000000000 R14: 0000000000000000 R15: 00002000003d9000
 ____sys_recvmsg+0x2ab/0x460 net/socket.c:2799
 ___sys_recvmsg+0x1b5/0x510 net/socket.c:2828
 do_recvmmsg+0x307/0x770 net/socket.c:2923
 __sys_recvmmsg net/socket.c:2997 [inline]
 __do_sys_recvmmsg net/socket.c:3020 [inline]
 __se_sys_recvmmsg net/socket.c:3013 [inline]
 __x64_sys_recvmmsg+0x190/0x240 net/socket.c:3013
 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
RIP: 0033:0x7fc6b1d8e969
RSP: 002b:00007fc6b2b2e038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007fc6b1fb6080 RCX: 00007fc6b1d8e969
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007fc6b1e10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007fc6b1fb6080 R15: 00007fc6b20dfa28
 </TASK>
rcu: rcu_preempt kthread starved for 10500 jiffies! g19813 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:27128 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5392 [inline]
 __schedule+0x16f5/0x4d00 kernel/sched/core.c:6781
 __schedule_loop kernel/sched/core.c:6859 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6874
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256
 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
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.15.0-syzkaller-09113-g8477ab143069 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 43 d5 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 c3 a2 24 00 f3 0f 1e fa fb f4 <e9> 18 d5 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0000:ffffffff8de07d80 EFLAGS: 000002c6
RAX: 395abc25ae8c3000 RBX: ffffffff81975388 RCX: 395abc25ae8c3000
RDX: 0000000000000001 RSI: ffffffff8d96e646 RDI: ffffffff8be26580
RBP: ffffffff8de07ea8 R08: ffff8880b8632f5b R09: 1ffff110170c65eb
R10: dffffc0000000000 R11: ffffed10170c65ec R12: ffffffff8fa0a8f0
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1bd2a48
FS:  0000000000000000(0000) GS:ffff888125c65000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1ca98c0846 CR3: 000000007d012000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:743
 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:743
 start_kernel+0x478/0x500 init/main.c:1099
 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
 </TASK>