rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P21460/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=101325, q=141 ncpus=2)
task:syz.4.3745 state:R running task stack:26504 pid:21460 tgid:21454 ppid:18525 task_flags:0x400040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190
irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:rcu_read_lock_sched_held kernel/rcu/update.c:126 [inline]
RIP: 0010:rcu_read_lock_sched_held+0x49/0x70 kernel/rcu/update.c:120
Code: 00 84 c0 74 41 e8 b7 f0 00 00 84 c0 74 38 be ff ff ff ff 48 c7 c7 60 95 3c 8e e8 12 d4 d4 09 85 c0 75 d1 65 8b 05 37 4e 0f 12 ff ff ff 7f 75 c3 9c 5b 48 c1 eb 09 48 83 f3 01 83 e3 01 89 d8
RSP: 0018:ffffc9001d3a7850 EFLAGS: 00000246
RAX: 0000000080000000 RBX: 0000000000000001 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff8da9be65 RDI: ffffffff8bf23a80
RBP: ffff88802233f800 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: ffff888039d08b30 R12: ffff88807c0a0000
R13: ffff88807b6adc90 R14: 0000000000000000 R15: 0000000000000000
task_css.constprop.0+0x66/0x130 include/linux/cgroup.h:460
count_memcg_events_mm.constprop.0+0xae/0x2a0 include/linux/memcontrol.h:983
count_memcg_event_mm include/linux/memcontrol.h:992 [inline]
mm_account_fault mm/memory.c:6445 [inline]
handle_mm_fault+0x5f9/0xad0 mm/memory.c:6606
do_user_addr_fault+0x7a6/0x1370 arch/x86/mm/fault.c:1387
handle_page_fault arch/x86/mm/fault.c:1476 [inline]
exc_page_fault+0x64/0xc0 arch/x86/mm/fault.c:1532
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0010:rep_movs_alternative+0x30/0x90 arch/x86/lib/copy_user_64.S:60
Code: 83 f9 08 73 25 85 c9 74 0f 8a 06 88 07 48 ff c7 48 ff c6 48 ff c9 75 f1 e9 7d 81 04 00 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 <48> 8b 06 48 89 07 48 83 c6 08 48 83 c7 08 83 e9 08 74 db 83 f9 08
RSP: 0018:ffffc9001d3a7a48 EFLAGS: 00050206
RAX: 0000000000000001 RBX: 00002000000d0000 RCX: 0000000000000038
RDX: fffff52003a74f5a RSI: 00002000000d0000 RDI: ffffc9001d3a7a98
RBP: 0000000000000038 R08: 0000000000000001 R09: fffff52003a74f59
R10: ffffc9001d3a7acf R11: ffff888039d08b30 R12: 0000000000000000
R13: ffffc9001d3a7a98 R14: ffffc9001d3a7b80 R15: ffffc9001d3a7a98
copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline]
raw_copy_from_user arch/x86/include/asm/uaccess_64.h:141 [inline]
_inline_copy_from_user include/linux/uaccess.h:185 [inline]
_copy_from_user+0x98/0xd0 lib/usercopy.c:18
copy_from_user include/linux/uaccess.h:223 [inline]
copy_msghdr_from_user+0x98/0x160 net/socket.c:2522
recvmsg_copy_msghdr net/socket.c:2778 [inline]
___sys_recvmsg+0xdb/0x1a0 net/socket.c:2850
do_recvmmsg+0x2fe/0x750 net/socket.c:2949
__sys_recvmmsg net/socket.c:3023 [inline]
__do_sys_recvmmsg net/socket.c:3046 [inline]
__se_sys_recvmmsg net/socket.c:3039 [inline]
__x64_sys_recvmmsg+0x22a/0x280 net/socket.c:3039
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb0d338f749
RSP: 002b:00007fb0d42e8038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007fb0d35e6090 RCX: 00007fb0d338f749
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000005
RBP: 00007fb0d3413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb0d35e6128 R14: 00007fb0d35e6090 R15: 00007ffc4570be38
rcu: rcu_preempt kthread starved for 10534 jiffies! g101325 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:28120 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 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 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 06 60 02 c3 cc cc cc cc 0f 1f 00 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 13 59 13 00 fb f4 cc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffffff8e007df8 EFLAGS: 000002c6
RAX: 0000000006e218d1 RBX: 0000000000000000 RCX: ffffffff8b7706d9
RDX: 0000000000000000 RSI: ffffffff8dac1f05 RDI: ffffffff8bf23a80
RBP: fffffbfff1c12f68 R08: 0000000000000001 R09: ffffed101708673d
R10: ffff8880b84339eb R11: ffffffff8e098670 R12: 0000000000000000
R13: ffffffff8e097b40 R14: ffffffff9087fbd0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888124909000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7c309592ae CR3: 00000000354f4000 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+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x38d/0x510 kernel/sched/idle.c:332
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430
rest_init+0x16b/0x2b0 init/main.c:757
start_kernel+0x3ef/0x4d0 init/main.c:1206
x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x148