rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=c17c/1/0x4000000000000000 softirq=24223/24224 fqs=0
rcu: (detected by 1, t=10502 jiffies, g=20745, q=146 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 8062 Comm: syz.3.502 Not tainted 6.14.0-rc4-syzkaller-00278-gece144f151ac #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4852 [inline]
RIP: 0010:__lock_acquire+0x57d/0x2100 kernel/locking/lockdep.c:5178
Code: 8c e8 67 bd e4 ff 48 ba 00 00 00 00 00 fc ff df 90 0f 0b 90 90 90 31 db 48 81 c3 c4 00 00 00 48 89 d8 48 c1 e8 03 0f b6 04 10 <84> c0 0f 85 f8 12 00 00 0f b6 2b 41 0f b6 04 16 84 c0 0f 85 0c 13
RSP: 0018:ffffc90000007a10 EFLAGS: 00000803
RAX: 0000000000000000 RBX: ffffffff93e8d18c RCX: ffffffff819cbc9c
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffffffff94513840
RBP: 00000000000a4021 R08: ffffffff94513847 R09: 1ffffffff28a2708
R10: dffffc0000000000 R11: fffffbfff28a2709 R12: ffff888078f5a8d4
R13: 0000000000000005 R14: 1ffff1100f1eb527 R15: ffff888078f5a938
FS: 00007f324ebf96c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30518000 CR3: 000000005f07e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
rcu_read_lock include/linux/rcupdate.h:849 [inline]
advance_sched+0xa1e/0xca0 net/sched/sch_taprio.c:985
__run_hrtimer kernel/time/hrtimer.c:1801 [inline]
__hrtimer_run_queues+0x59b/0xd30 kernel/time/hrtimer.c:1865
hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1927
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline]
__sysvec_apic_timer_interrupt+0x110/0x420 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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194
Code: 9c 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 ae 1d 23 f6 f6 44 24 21 02 75 52 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 43 0d 8c f5 65 8b 05 94 7f 00 74 85 c0 74 43 48 c7 04 24 0e 36
RSP: 0018:ffffc9000cd67620 EFLAGS: 00000206
RAX: b6708c68380d5f00 RBX: 1ffff920019acec8 RCX: ffffffff819d2a9a
RDX: dffffc0000000000 RSI: ffffffff8c2aa4a0 RDI: 0000000000000001
RBP: ffffc9000cd676b0 R08: ffffffff945138ff R09: 1ffffffff28a271f
R10: dffffc0000000000 R11: fffffbfff28a2720 R12: dffffc0000000000
R13: 1ffff920019acec4 R14: ffffc9000cd67640 R15: 0000000000000246
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
__wake_up_common_lock+0x18c/0x1e0 kernel/sched/wait.c:108
__unix_dgram_recvmsg+0x61a/0x1320 net/unix/af_unix.c:2457
sock_recvmsg_nosec+0x18e/0x1d0 net/socket.c:1023
____sys_recvmsg+0x3cd/0x480 net/socket.c:2791
___sys_recvmsg net/socket.c:2835 [inline]
do_recvmmsg+0x426/0xab0 net/socket.c:2930
__sys_recvmmsg net/socket.c:3004 [inline]
__do_sys_recvmmsg net/socket.c:3027 [inline]
__se_sys_recvmmsg net/socket.c:3020 [inline]
__x64_sys_recvmmsg+0x199/0x250 net/socket.c:3020
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: 0033:0x7f324dd8d169
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:00007f324ebf9038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f324dfa6080 RCX: 00007f324dd8d169
RDX: 0000000000010106 RSI: 00004000000000c0 RDI: 0000000000000004
RBP: 00007f324de0e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f324dfa6080 R15: 00007ffcfdd4bb58
rcu: rcu_preempt kthread starved for 10502 jiffies! g20745 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:25784 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5378 [inline]
__schedule+0x18bc/0x4c40 kernel/sched/core.c:6765
__schedule_loop kernel/sched/core.c:6842 [inline]
schedule+0x14b/0x320 kernel/sched/core.c:6857
schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2024
rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2226
kthread+0x7a9/0x920 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
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: 11 Comm: kworker/u8:0 Not tainted 6.14.0-rc4-syzkaller-00278-gece144f151ac #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: writeback wb_workfn (flush-8:0)
RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline]
RIP: 0010:smp_call_function_many_cond+0x1ba4/0x2d30 kernel/smp.c:885
Code: 03 84 c0 75 7e 45 8b 65 00 44 89 e6 83 e6 01 31 ff e8 30 f5 0b 00 41 83 e4 01 4c 8b 64 24 68 75 07 e8 e0 f0 0b 00 eb 41 f3 90 <48> b8 00 00 00 00 00 fc ff df 0f b6 04 03 84 c0 75 11 41 f7 45 00
RSP: 0018:ffffc90000105f20 EFLAGS: 00000293
RAX: ffffffff81b5ce05 RBX: 1ffff110170c8c75 RCX: ffff88801c683c00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000106120 R08: ffffffff81b5cdd0 R09: 1ffff92000020bd4
R10: dffffc0000000000 R11: fffff52000020bd5 R12: ffff8880b873f9c8
R13: ffff8880b86463a8 R14: ffff8880b873f9c0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b304d4480 CR3: 000000005f07e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 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:966 [inline]
flush_tlb_mm_range+0x42d/0x710 arch/x86/mm/tlb.c:1054
flush_tlb_page arch/x86/include/asm/tlbflush.h:255 [inline]
ptep_clear_flush+0x11a/0x170 mm/pgtable-generic.c:101
page_vma_mkclean_one+0x58a/0x9a0 mm/rmap.c:1051
page_mkclean_one+0x272/0x350 mm/rmap.c:1092
rmap_walk_file+0x502/0x780 mm/rmap.c:2708
rmap_walk mm/rmap.c:2726 [inline]
folio_mkclean+0x252/0x370 mm/rmap.c:1124
folio_clear_dirty_for_io+0x219/0x950 mm/page-writeback.c:3018
mpage_submit_folio+0x84/0x340 fs/ext4/inode.c:1913
mpage_process_page_bufs+0x6d1/0x9d0 fs/ext4/inode.c:2045
mpage_prepare_extent_to_map+0xecb/0x1860 fs/ext4/inode.c:2546
ext4_do_writepages+0xc2a/0x3df0 fs/ext4/inode.c:2688
ext4_writepages+0x213/0x3c0 fs/ext4/inode.c:2824
do_writepages+0x35f/0x880 mm/page-writeback.c:2687
__writeback_single_inode+0x14f/0x10d0 fs/fs-writeback.c:1680
writeback_sb_inodes+0x820/0x1360 fs/fs-writeback.c:1976
__writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:2047
wb_writeback+0x427/0xb80 fs/fs-writeback.c:2158
wb_check_old_data_flush fs/fs-writeback.c:2262 [inline]
wb_do_writeback fs/fs-writeback.c:2315 [inline]
wb_workfn+0xb94/0x1080 fs/fs-writeback.c:2343
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3319
worker_thread+0x870/0xd30 kernel/workqueue.c:3400
kthread+0x7a9/0x920 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244