syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P7734/2:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=19597, q=598 ncpus=2)
task:syz.4.450       state:R  running task     stack:23744 pid:7734  tgid:7729  ppid:5835   task_flags:0x400040 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5378 [inline]
 __schedule+0x18bc/0x4c40 kernel/sched/core.c:6765
 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7087
 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_is_held_type+0x13b/0x190
Code: 75 44 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 4c 41 f7 c4 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 42 89 d8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f
RSP: 0018:ffffc9000ce8f0e0 EFLAGS: 00000206
RAX: 7b72f0f5fad72500 RBX: 0000000000000000 RCX: ffff88802ff48000
RDX: ffff88802ff48000 RSI: ffffffff8c2ab680 RDI: ffffffff8c801a80
RBP: 0000000000000003 R08: ffffffff8bfe2a27 R09: ffffffff8bfeaa7b
R10: 0000000000000002 R11: ffff88802ff48000 R12: 0000000000000246
R13: ffff88802ff48000 R14: 00000000ffffffff R15: ffff888058b28a48
 lock_is_held include/linux/lockdep.h:249 [inline]
 xa_entry include/linux/xarray.h:1220 [inline]
 xas_descend lib/xarray.c:208 [inline]
 xas_load+0x19c/0x5c0 lib/xarray.c:246
 xas_find+0x13f/0x960 lib/xarray.c:1273
 next_uptodate_folio+0x33/0x5f0 mm/filemap.c:3628
 filemap_map_pages+0x2ea/0x1900 mm/filemap.c:3780
 do_fault_around mm/memory.c:5361 [inline]
 do_read_fault mm/memory.c:5394 [inline]
 do_fault mm/memory.c:5537 [inline]
 do_pte_missing mm/memory.c:4058 [inline]
 handle_pte_fault mm/memory.c:5900 [inline]
 __handle_mm_fault+0x4acb/0x70f0 mm/memory.c:6043
 handle_mm_fault+0x2c1/0x7e0 mm/memory.c:6212
 faultin_page mm/gup.c:1196 [inline]
 __get_user_pages+0x1a92/0x4140 mm/gup.c:1491
 populate_vma_page_range+0x264/0x330 mm/gup.c:1929
 __mm_populate+0x27a/0x460 mm/gup.c:2032
 mm_populate include/linux/mm.h:3386 [inline]
 vm_mmap_pgoff+0x303/0x430 mm/util.c:580
 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: 0033:0x7f869178d169
RSP: 002b:00007f869256a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f86919a6080 RCX: 00007f869178d169
RDX: b635773f06ebbeef RSI: 0000000000b36000 RDI: 0000400000000000
RBP: 00007f869180e2a0 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f86919a6080 R15: 00007fff0dd8d528
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g19597 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=12273
rcu: rcu_preempt kthread starved for 10500 jiffies! g19597 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:26104 pid:17    tgid:17    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 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
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5938 Comm: kworker/u8:8 Not tainted 6.14.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: iou_exit io_ring_exit_work
RIP: 0010:mark_usage kernel/locking/lockdep.c:4639 [inline]
RIP: 0010:__lock_acquire+0xbde/0x2100 kernel/locking/lockdep.c:5182
Code: 31 f6 4c 89 ef 48 89 ee 31 d2 e8 4d 66 00 00 48 ba 00 00 00 00 00 fc ff df 85 c0 0f 84 4e 08 00 00 48 8b 44 24 50 0f b6 04 10 <84> c0 0f 85 88 11 00 00 41 83 3c 24 00 48 8b 5c 24 18 74 22 4c 89
RSP: 0018:ffffc90000a18a10 EFLAGS: 00000002
RAX: 0000000000000000 RBX: 1ffff1100fffd531 RCX: ffffffff819d296a
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffffffff94511990
RBP: ffff88807ffea968 R08: ffffffff94511997 R09: 1ffffffff28a2332
R10: dffffc0000000000 R11: fffffbfff28a2333 R12: ffff88807ffea8d4
R13: ffff88807ffe9e00 R14: 0000000000000000 R15: ffff88807ffea988
FS:  0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000040000001e000 CR3: 000000005a282000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:351 [inline]
 advance_sched+0xab/0xca0 net/sched/sch_taprio.c:924
 __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
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:memset_orig+0x6a/0xb0 arch/x86/lib/memset_64.S:85
Code: 47 18 48 89 47 20 48 89 47 28 48 89 47 30 48 89 47 38 48 8d 7f 40 75 d8 0f 1f 84 00 00 00 00 00 89 d1 83 e1 38 74 14 c1 e9 03 <66> 0f 1f 44 00 00 ff c9 48 89 07 48 8d 7f 08 75 f5 83 e2 07 74 0a
RSP: 0018:ffffc900044df328 EFLAGS: 00000202
RAX: 0000000000000000 RBX: ffffc900044df438 RCX: 0000000000000002
RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffffc900044df450
RBP: dffffc0000000000 R08: ffffc900044df45f R09: 0000000000000000
R10: ffffc900044df450 R11: fffff5200089be8c R12: ffffc900044e0000
R13: ffffc900044df400 R14: ffffffff8129dbaa R15: ffffc900044df450
 unwind_next_frame+0xcfb/0x22d0 arch/x86/kernel/unwind_orc.c:592
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122
 kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47
 kasan_record_aux_stack+0xaa/0xc0 mm/kasan/generic.c:548
 __call_rcu_common kernel/rcu/tree.c:3065 [inline]
 call_rcu+0x168/0xac0 kernel/rcu/tree.c:3172
 slab_free_hook mm/slub.c:2317 [inline]
 slab_free mm/slub.c:4609 [inline]
 kmem_cache_free+0x30e/0x410 mm/slub.c:4711
 io_req_caches_free+0xa7/0x120 io_uring/io_uring.c:2690
 io_ring_exit_work+0x382/0x8a0 io_uring/io_uring.c:2889
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3317
 worker_thread+0x870/0xd30 kernel/workqueue.c:3398
 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
 </TASK>