rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9045/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=28261, q=82 ncpus=2)
task:syz.1.798 state:R running task stack:25592 pid:9045 tgid:9044 ppid:5829 task_flags:0x40054c flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x168f/0x4c70 kernel/sched/core.c:6767
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7090
irqentry_exit+0x6f/0x90 kernel/entry/common.c:354
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5870
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 4b e2 d3 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc9000f126b58 EFLAGS: 00000206
RAX: 66c90bd4f1369400 RBX: 0000000000000000 RCX: 66c90bd4f1369400
RDX: 0000000000000000 RSI: ffffffff8d921419 RDI: ffffffff8bc0fee0
RBP: ffffffff8171a9f5 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8171a9f5 R12: 0000000000000002
R13: ffffffff8df3b860 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf7/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:308
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1262 [inline]
free_unref_folios+0xb70/0x1490 mm/page_alloc.c:2782
folios_put_refs+0x559/0x640 mm/swap.c:992
free_pages_and_swap_cache+0x277/0x520 mm/swap_state.c:267
__tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline]
tlb_batch_pages_flush mm/mmu_gather.c:149 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:397 [inline]
tlb_flush_mmu+0x3a0/0x680 mm/mmu_gather.c:404
zap_pte_range mm/memory.c:1770 [inline]
zap_pmd_range mm/memory.c:1823 [inline]
zap_pud_range mm/memory.c:1852 [inline]
zap_p4d_range mm/memory.c:1873 [inline]
unmap_page_range+0x37fd/0x4210 mm/memory.c:1894
unmap_vmas+0x25d/0x3c0 mm/memory.c:1984
exit_mmap+0x245/0xba0 mm/mmap.c:1284
__mmput+0x118/0x410 kernel/fork.c:1379
exit_mm+0x1da/0x2c0 kernel/exit.c:589
do_exit+0x859/0x2550 kernel/exit.c:940
do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
get_signal+0x125e/0x1310 kernel/signal.c:3034
arch_do_signal_or_restart+0x95/0x780 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x8b/0x120 kernel/entry/common.c:218
do_syscall_64+0x103/0x210 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0af698e969
RSP: 002b:00007f0af7790038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: fffffffffffffff2 RBX: 00007f0af6bb5fa0 RCX: 00007f0af698e969
RDX: 0000200000000300 RSI: 0000000080104592 RDI: 0000000000000005
RBP: 00007f0af6a10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f0af6bb5fa0 R15: 00007ffe222bea88
rcu: rcu_preempt kthread starved for 10491 jiffies! g28261 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:27032 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x168f/0x4c70 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6860
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2046
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2248
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 9074 Comm: syz.0.802 Not tainted 6.15.0-rc5-syzkaller-00136-g9c69f8884904 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025
RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline]
RIP: 0010:smp_call_function_many_cond+0xe69/0x11c0 kernel/smp.c:885
Code: 00 45 8b 2f 44 89 ee 83 e6 01 31 ff e8 10 6d 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 bb 68 0b 00 eb 37 f3 90 <43> 0f b6 04 2c 84 c0 75 10 41 f7 07 01 00 00 00 74 1e e8 a0 68 0b
RSP: 0018:ffffc9000b916fe0 EFLAGS: 00000246
RAX: ffffffff81b466c0 RBX: ffff8880b883abc0 RCX: 0000000000080000
RDX: ffffc9000d2ce000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc9000b917140 R08: ffffffff8f7da777 R09: 1ffffffff1efb4ee
R10: dffffc0000000000 R11: fffffbfff1efb4ef R12: 1ffff11017127e69
R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b893f348
FS: 00007f442f88f6c0(0000) GS:ffff888126100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000078030 CR3: 000000007bd80000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 00000000000032e7 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052
__flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1275 [inline]
flush_tlb_mm_range+0x6ae/0x12b0 arch/x86/mm/tlb.c:1365
flush_tlb_page arch/x86/include/asm/tlbflush.h:324 [inline]
ptep_clear_flush+0x120/0x170 mm/pgtable-generic.c:101
wp_page_copy mm/memory.c:3544 [inline]
do_wp_page+0x1b5e/0x5760 mm/memory.c:3939
handle_pte_fault mm/memory.c:6013 [inline]
__handle_mm_fault+0x1028/0x5380 mm/memory.c:6140
handle_mm_fault+0x2d5/0x7f0 mm/memory.c:6309
do_user_addr_fault+0x764/0x1390 arch/x86/mm/fault.c:1388
handle_page_fault arch/x86/mm/fault.c:1480 [inline]
exc_page_fault+0x68/0x110 arch/x86/mm/fault.c:1538
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 c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc9000b9178d8 EFLAGS: 00050202
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000200000078030
RDX: ffff88801e76da00 RSI: 0000000000000002 RDI: 00000000ffffffff
RBP: ffffc9000b917a50 R08: ffffc9000b917687 R09: 1ffff92001722ed0
R10: dffffc0000000000 R11: fffff52001722ed1 R12: 0000000000000002
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000200000078000
____sys_recvmsg+0x2ab/0x460 net/socket.c:2799
___sys_recvmsg+0x1b5/0x510 net/socket.c:2828
do_recvmmsg+0x307/0x760 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+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f442e98e969
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:00007f442f88f038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f442ebb6080 RCX: 00007f442e98e969
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007f442ea10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f442ebb6080 R15: 00007fff380d5128