rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5965/1:b..l P5976/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=218909, q=664 ncpus=2)
task:syz.9.8726 state:R running task stack:24968 pid:5976 tgid:5966 ppid:31474 task_flags:0x400040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5257 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6864
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7191
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:rcu_read_unlock include/linux/rcupdate.h:895 [inline]
RIP: 0010:class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
RIP: 0010:unwind_next_frame+0x1957/0x2390 arch/x86/kernel/unwind_orc.c:680
Code: c0 0f 85 9b 03 00 00 c6 03 01 4c 8b 7c 24 48 4c 8b 64 24 20 41 0f b6 04 2c 84 c0 0f 85 2d 03 00 00 41 c7 06 00 00 00 00 31 db c4 0f e5 09 85 c0 74 3a e8 2b 44 33 00 84 c0 75 31 e8 b2 0f e5
RSP: 0018:ffffc9000450ec38 EFLAGS: 00000206
RAX: ffffc90004510000 RBX: ffffffff90221e01 RCX: ffffc9000450f430
RDX: ffffc9000450ed01 RSI: dffffc0000000000 RDI: ffffc9000450ed10
RBP: dffffc0000000000 R08: ffffc9000450f418 R09: 0000000000000000
R10: ffffc9000450ed58 R11: fffff520008a1dad R12: ffffc9000450f428
R13: ffffc90004508000 R14: ffffc9000450ed08 R15: ffffffff81743f85
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 mm/page_owner.c:165
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:320
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1395 [inline]
__free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2943
__folio_put+0x21b/0x2c0 mm/swap.c:112
folio_put_refs include/linux/mm.h:1637 [inline]
collapse_file mm/khugepaged.c:2244 [inline]
hpage_collapse_scan_file+0x4711/0x4f10 mm/khugepaged.c:2387
madvise_collapse+0x444/0xa30 mm/khugepaged.c:2810
madvise_vma_behavior+0xfca/0x4170 mm/madvise.c:1372
madvise_walk_vmas+0x575/0xaf0 mm/madvise.c:1721
madvise_do_behavior+0x38e/0x550 mm/madvise.c:1937
do_madvise+0x1bc/0x270 mm/madvise.c:2030
__do_sys_madvise mm/madvise.c:2039 [inline]
__se_sys_madvise mm/madvise.c:2037 [inline]
__x64_sys_madvise+0xa7/0xc0 mm/madvise.c:2037
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fea4b38f749
RSP: 002b:00007fea4c1f5038 EFLAGS: 00000246 ORIG_RAX: 000000000000001c
RAX: ffffffffffffffda RBX: 00007fea4b5e6090 RCX: 00007fea4b38f749
RDX: 0000000000000019 RSI: 0000000000600003 RDI: 0000200000000000
RBP: 00007fea4b413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fea4b5e6128 R14: 00007fea4b5e6090 R15: 00007ffc01e094b8
task:syz.5.8723 state:R running task stack:24808 pid:5965 tgid:5962 ppid:5107 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5257 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6864
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7191
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:217 [inline]
RIP: 0010:unwind_next_frame+0x214/0x2390 arch/x86/kernel/unwind_orc.c:494
Code: ef 08 8b 15 5e f2 25 0c 8d 42 ff 44 39 f8 0f 86 65 18 00 00 44 89 f8 4c 8d 2c 85 c0 93 bf 90 4c 89 e8 48 c1 e8 03 0f b6 04 28 <84> c0 48 89 eb 0f 85 1c 1c 00 00 45 8b 6d 00 44 89 f8 ff c0 48 8d
RSP: 0018:ffffc900047869f8 EFLAGS: 00000a07
RAX: 0000000000000000 RBX: 0000000000000001 RCX: aaa4da5725d0bc00
RDX: 00000000000a5d2e RSI: ffffffff8bc018c0 RDI: ffffffff8bc01880
RBP: dffffc0000000000 R08: ffffffff81743f85 R09: ffffffff8df419e0
R10: ffffc90004786b18 R11: ffffffff81ada230 R12: ffffffff81755513
R13: ffffffff90c16914 R14: ffffc90004786ac8 R15: 0000000000007555
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 mm/page_owner.c:165
__set_page_owner+0x8d/0x4c0 mm/page_owner.c:341
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x234/0x290 mm/page_alloc.c:1846
prep_new_page mm/page_alloc.c:1854 [inline]
get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3915
__alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
folio_alloc_mpol_noprof mm/mempolicy.c:2505 [inline]
vma_alloc_folio_noprof+0xe4/0x200 mm/mempolicy.c:2540
folio_prealloc+0x30/0x180 mm/memory.c:-1
wp_page_copy mm/memory.c:3719 [inline]
do_wp_page+0x1231/0x5810 mm/memory.c:4180
handle_pte_fault mm/memory.c:6289 [inline]
__handle_mm_fault mm/memory.c:6411 [inline]
handle_mm_fault+0x14c5/0x32b0 mm/memory.c:6580
do_user_addr_fault+0x764/0x1380 arch/x86/mm/fault.c:1387
handle_page_fault arch/x86/mm/fault.c:1476 [inline]
exc_page_fault+0x82/0x100 arch/x86/mm/fault.c:1532
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
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 d1 76 03 00 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc900047878b8 EFLAGS: 00050202
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000200000141030
RDX: 00000000003fffe0 RSI: 0000000000000002 RDI: 00000000ffffffff
RBP: ffffc90004787a30 R08: 000000000001ffff R09: 0000000000400000
R10: 0000000000400008 R11: fffff520008f0ecd R12: 0000000000000002
R13: 0000200000141000 R14: 0000000000000000 R15: dffffc0000000000
____sys_recvmsg+0x2f5/0x4c0 net/socket.c:2834
___sys_recvmsg+0x1b5/0x510 net/socket.c:2863
do_recvmmsg+0x307/0x770 net/socket.c:2958
__sys_recvmmsg net/socket.c:3032 [inline]
__do_sys_recvmmsg net/socket.c:3055 [inline]
__se_sys_recvmmsg net/socket.c:3048 [inline]
__x64_sys_recvmmsg+0x190/0x240 net/socket.c:3048
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fce0dd8f749
RSP: 002b:00007fce0ebd1038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007fce0dfe6090 RCX: 00007fce0dd8f749
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007fce0de13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fce0dfe6128 R14: 00007fce0dfe6090 R15: 00007ffd52179128
rcu: rcu_preempt kthread starved for 10610 jiffies! g218909 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:27104 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5257 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6864
__schedule_loop kernel/sched/core.c:6946 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6961
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+0x599/0xb30 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: 5978 Comm: syz.2.8729 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:_static_cpu_has arch/x86/include/asm/cpufeature.h:101 [inline]
RIP: 0010:pkru_write_default arch/x86/include/asm/pkru.h:56 [inline]
RIP: 0010:restore_fpregs_from_init_fpstate arch/x86/kernel/fpu/core.c:775 [inline]
RIP: 0010:fpu__clear_user_states+0x1a9/0x420 arch/x86/kernel/fpu/core.c:833
Code: e8 bc 03 58 00 be ff 00 0e 00 48 c7 c7 40 a7 99 8d ba 01 00 00 00 e8 96 7a 00 00 b8 ff 00 0e 00 31 d2 48 0f ae 2d e7 f7 2f 0c ef 01 00 00 e8 8d 03 58 00 48 c7 c0 20 74 dc 8d 48 c1 e8 03 42
RSP: 0018:ffffc900042efd20 EFLAGS: 00000246
RAX: 00000000000e00ff RBX: ffff888033043d00 RCX: 0000000000080000
RDX: 0000000000000000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: 0000000000000000 R08: ffffffff820f6420 R09: ffff888057ff8340
R10: dffffc0000000000 R11: fffff5200085dfbe R12: ffff888033045700
R13: dffffc0000000000 R14: ffff888033043d2c R15: 1ffff110066087a5
FS: 00007f0b690026c0(0000) GS:ffff888125e4f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000bbdffc CR3: 000000004e720000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 3a810b1eb6134bdc DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
handle_signal arch/x86/kernel/signal.c:310 [inline]
arch_do_signal_or_restart+0x44c/0x7a0 arch/x86/kernel/signal.c:339
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2e3/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0b681b7e80
Code: 83 c0 16 83 e0 f7 74 12 50 48 8d 3d 8a 54 08 00 e8 05 8f f8 ff 0f 1f 44 00 00 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 <83> ff 21 74 0b c3 66 2e 0f 1f 84 00 00 00 00 00 55 53 48 89 f3 48
RSP: 002b:0000200000004af8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007f0b683e6090 RCX: 00007f0b6818f749
RDX: 0000200000004b00 RSI: 0000200000004c30 RDI: 0000000000000021
RBP: 00007f0b68213f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0b683e6128 R14: 00007f0b683e6090 R15: 00007ffe773605b8