rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: (detected by 0, t=10503 jiffies, g=55369, q=269 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 7197 (4294988719-4294981522), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 7197 jiffies! g55369 f0x2 RCU_GP_WAIT_FQS(5) ->state=R ->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:26112 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5583 [inline]
__schedule+0x17dd/0x5820 kernel/sched/core.c:7382
__schedule_loop kernel/sched/core.c:7459 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7474
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x30c/0x1230 kernel/rcu/tree.c:2122
rcu_gp_kthread+0x9c/0x340 kernel/rcu/tree.c:2330
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
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: 43 Comm: kworker/u8:2 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Workqueue: writeback wb_workfn (flush-8:0)
RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x80 kernel/kcov.c:212
Code: 8b 3d 34 3a ad 0c 48 89 de 5b e9 e3 c3 6a 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0d c8 f9 d3 12 65 48 8b 15 c8 f9 d3 12 f7 c2 00 01 00 ff
RSP: 0018:ffffc90000b36118 EFLAGS: 00000202
RAX: ffffffff81bc94f8 RBX: ffff8880b8541b08 RCX: ffff88801fac8000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000b36270 R08: ffff888033422407 R09: 1ffff11006684480
R10: dffffc0000000000 R11: ffffffff817a5570 R12: 1ffff110170a8361
R13: dffffc0000000000 R14: 1ffff11003f592b3 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888123a51000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3a91a3ef0d CR3: 000000007c4ea000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
csd_lock_wait kernel/smp.c:389 [inline]
smp_call_function_many_cond+0x1148/0x1500 kernel/smp.c:1028
__flush_tlb_multi arch/x86/include/asm/paravirt.h:46 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline]
flush_tlb_mm_range+0x910/0x10b0 arch/x86/mm/tlb.c:1435
flush_tlb_page arch/x86/include/asm/tlbflush.h:352 [inline]
ptep_clear_flush+0x120/0x170 mm/pgtable-generic.c:116
page_vma_mkclean_one+0x4b4/0x830 mm/rmap.c:1144
page_mkclean_one+0x20c/0x2e0 mm/rmap.c:1192
__rmap_walk_file+0x4c8/0x6a0 mm/rmap.c:3115
rmap_walk mm/rmap.c:3159 [inline]
folio_mkclean+0x2d5/0x3f0 mm/rmap.c:1224
folio_clear_dirty_for_io+0x190/0x820 mm/page-writeback.c:2903
mpage_submit_folio+0x83/0x2a0 fs/ext4/inode.c:2075
mpage_process_page_bufs+0x6bd/0x8a0 fs/ext4/inode.c:2201
mpage_prepare_extent_to_map+0xf8d/0x1880 fs/ext4/inode.c:2743
ext4_do_writepages+0xb8a/0x4770 fs/ext4/inode.c:2884
ext4_writepages+0x1fe/0x4e0 fs/ext4/inode.c:3032
do_writepages+0x338/0x560 mm/page-writeback.c:2560
__writeback_single_inode+0x136/0x1220 fs/fs-writeback.c:1800
writeback_sb_inodes+0x9de/0x1af0 fs/fs-writeback.c:2111
__writeback_inodes_wb+0x114/0x240 fs/fs-writeback.c:2187
wb_writeback+0x42f/0xad0 fs/fs-writeback.c:2298
wb_check_old_data_flush fs/fs-writeback.c:2402 [inline]
wb_do_writeback fs/fs-writeback.c:2481 [inline]
wb_workfn+0xc92/0x10f0 fs/fs-writeback.c:2509
process_one_work kernel/workqueue.c:3495 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245