rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P48/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=10033, q=345 ncpus=2)
task:kworker/u4:3    state:R  running task     stack:22008 pid:48    ppid:2      flags:0x00004000
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x14e2/0x4580 kernel/sched/core.c:6700
 preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7010
 irqentry_exit+0x67/0x70 kernel/entry/common.c:438
 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:692
RIP: 0010:instrument_atomic_read include/linux/instrumented.h:68 [inline]
RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]
RIP: 0010:folio_memcg_lock+0x18f/0x2f0 mm/memcontrol.c:2136
Code: 48 c7 44 24 60 00 00 00 00 9c 8f 44 24 60 f6 44 24 61 02 0f 85 85 00 00 00 41 f7 c5 00 02 00 00 74 01 fb 4d 8d a7 40 09 00 00 <4c> 89 e7 be 04 00 00 00 e8 b4 ef f8 ff 4c 89 e0 48 c1 e8 03 48 b9
RSP: 0018:ffffc90000b8eae0 EFLAGS: 00000206
RAX: d354543559192c00 RBX: ffffea0001cee0c0 RCX: d354543559192c00
RDX: dffffc0000000000 RSI: ffffffff8aaab940 RDI: ffffffff8afc7880
RBP: ffffc90000b8ebb0 R08: ffffffff90da65c7 R09: 1ffffffff21b4cb8
R10: dffffc0000000000 R11: fffffbfff21b4cb9 R12: ffff88814125a940
R13: 0000000000000286 R14: ffffffff81e55649 R15: ffff88814125a000
 __folio_start_writeback+0x15d/0xf80 mm/page-writeback.c:3017
 ext4_bio_write_folio+0xedc/0x2250 fs/ext4/page-io.c:566
 mpage_submit_folio+0x237/0x3c0 fs/ext4/inode.c:1908
 mpage_map_and_submit_buffers fs/ext4/inode.c:2154 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2293 [inline]
 ext4_do_writepages+0x1d01/0x38d0 fs/ext4/inode.c:2718
 ext4_writepages+0x1a8/0x2f0 fs/ext4/inode.c:2807
 do_writepages+0x3a2/0x600 mm/page-writeback.c:2575
 __writeback_single_inode+0x153/0xee0 fs/fs-writeback.c:1625
 writeback_sb_inodes+0x77c/0xef0 fs/fs-writeback.c:1916
 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:1987
 wb_writeback+0x464/0xba0 fs/fs-writeback.c:2097
 wb_check_old_data_flush fs/fs-writeback.c:2201 [inline]
 wb_do_writeback fs/fs-writeback.c:2254 [inline]
 wb_workfn+0xabc/0xe20 fs/fs-writeback.c:2282
 process_one_work kernel/workqueue.c:2634 [inline]
 process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
rcu: rcu_preempt kthread starved for 10447 jiffies! g10033 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:27496 pid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x14e2/0x4580 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_timeout+0x160/0x280 kernel/time/timer.c:2167
 rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667
 rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1866
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.6.97-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:148
Code: cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d 33 a6 39 00 f3 0f 1e fa fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc 66 0f 1f 00 55 41 57 41 56
RSP: 0018:ffffffff8ca07d80 EFLAGS: 000002c2
RAX: f59a2d84d7290700 RBX: ffffffff81618a7b RCX: f59a2d84d7290700
RDX: 0000000000000001 RSI: ffffffff8aaab940 RDI: ffffffff8afc7880
RBP: ffffffff8ca07eb8 R08: ffff8880b8e36d4b R09: 1ffff110171c6da9
R10: dffffc0000000000 R11: ffffed10171c6daa R12: ffffffff8e4a92e8
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1952670
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000002 CR3: 000000002ca37000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:753
 default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97
 cpuidle_idle_call kernel/sched/idle.c:170 [inline]
 do_idle+0x1eb/0x510 kernel/sched/idle.c:282
 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:380
 rest_init+0x2e2/0x300 init/main.c:732
 arch_call_rest_init+0xe/0x10 init/main.c:829
 start_kernel+0x459/0x4e0 init/main.c:1074
 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555
 x86_64_start_kernel+0x60/0x60 arch/x86/kernel/head64.c:536
 secondary_startup_64_no_verify+0x179/0x17b
 </TASK>