syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P8381/1:b..l P8014/1:b..l
	(detected by 0, t=10502 jiffies, g=36401, q=390 ncpus=2)
task:syz.8.899       state:R  running task     stack:22880 pid:8014  ppid:5348   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873
 irqentry_exit+0x63/0x70 kernel/entry/common.c:439
 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696
RIP: 0010:lock_acquire+0x20f/0x490 kernel/locking/lockdep.c:5666
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f5 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b
RSP: 0018:ffffc9000c1bf020 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 66a1d024ff38a100
RDX: 0000000000000000 RSI: ffffffff8a8c1700 RDI: ffffffff8adef3a0
RBP: ffffc9000c1bf138 R08: dffffc0000000000 R09: fffffbfff215c449
R10: fffffbfff215c449 R11: 1ffffffff215c448 R12: 0000000000000001
R13: 1ffff92001837e10 R14: 0000000000000246 R15: dffffc0000000000
 rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 rcu_read_lock include/linux/rcupdate.h:791 [inline]
 percpu_ref_put_many include/linux/percpu-refcount.h:330 [inline]
 percpu_ref_put+0x35/0x180 include/linux/percpu-refcount.h:351
 __mem_cgroup_uncharge_list+0x6c/0xc0 mm/memcontrol.c:7140
 mem_cgroup_uncharge_list include/linux/memcontrol.h:699 [inline]
 release_pages+0x1f8a/0x2200 mm/swap.c:1034
 __pagevec_release+0x6d/0xe0 mm/swap.c:1055
 pagevec_release include/linux/pagevec.h:71 [inline]
 folio_batch_release include/linux/pagevec.h:135 [inline]
 shmem_undo_range+0x75b/0x2050 mm/shmem.c:946
 shmem_truncate_range mm/shmem.c:1062 [inline]
 shmem_evict_inode+0x248/0xa40 mm/shmem.c:1171
 evict+0x485/0x870 fs/inode.c:705
 __dentry_kill+0x431/0x650 fs/dcache.c:611
 dentry_kill+0xb8/0x290 fs/dcache.c:-1
 dput+0xfa/0x1d0 fs/dcache.c:918
 __fput+0x5e0/0x920 fs/file_table.c:328
 task_work_run+0x1ca/0x250 kernel/task_work.c:203
 exit_task_work include/linux/task_work.h:39 [inline]
 do_exit+0x93e/0x2400 kernel/exit.c:880
 do_group_exit+0x217/0x2d0 kernel/exit.c:1022
 get_signal+0x1272/0x1350 kernel/signal.c:2871
 arch_do_signal_or_restart+0xb7/0x1240 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:316
 exc_page_fault+0x88/0x100 arch/x86/mm/fault.c:1490
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7f12da78efd1
RSP: 002b:fffffffffffffe70 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f12da9e6090 RCX: 00007f12da78efc9
RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000
RBP: 00007f12da811f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f12da9e6128 R14: 00007f12da9e6090 R15: 00007ffc66f19f08
 </TASK>
task:syz.1.990       state:R  running task     stack:25248 pid:8381  ppid:4268   flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873
 irqentry_exit+0x63/0x70 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:kthread_blkcg+0x28/0xd0 kernel/kthread.c:1528
Code: 00 00 55 41 57 41 56 53 49 bf 00 00 00 00 00 fc ff df e8 4b 18 2b 00 65 48 8b 1d 73 b4 ac 7e 4c 8d 73 2c 4c 89 f0 48 c1 e8 03 <42> 0f b6 04 38 84 c0 75 7b 41 8b 2e 89 ee 81 e6 00 00 20 00 31 ff
RSP: 0018:ffffc9000eccf4c0 EFLAGS: 00000a07
RAX: 1ffff1100501a3bd RBX: ffff8880280d1dc0 RCX: 0000000000080000
RDX: ffffc90010679000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff215c449
R10: fffffbfff215c449 R11: 1ffffffff215c448 R12: 0000000000000cc0
R13: dffffc0000000000 R14: ffff8880280d1dec R15: dffffc0000000000
 blkcg_css+0x10/0x1c0 block/blk-cgroup.c:74
 blk_cgroup_congested+0xba/0x220 block/blk-cgroup.c:2013
 __cgroup_throttle_swaprate+0x6d/0x1a0 mm/swapfile.c:3671
 cgroup_throttle_swaprate include/linux/swap.h:672 [inline]
 folio_throttle_swaprate include/linux/swap.h:681 [inline]
 shmem_add_to_page_cache+0x9c1/0x1c00 mm/shmem.c:717
 shmem_get_folio_gfp+0x158b/0x3400 mm/shmem.c:1971
 shmem_fault+0x1be/0x7b0 mm/shmem.c:2156
 __do_fault+0x13b/0x4e0 mm/memory.c:4280
 do_read_fault mm/memory.c:4631 [inline]
 do_fault mm/memory.c:4760 [inline]
 handle_pte_fault mm/memory.c:5031 [inline]
 __handle_mm_fault mm/memory.c:5173 [inline]
 handle_mm_fault+0x28bf/0x3e60 mm/memory.c:5294
 faultin_page mm/gup.c:1026 [inline]
 __get_user_pages+0x3ff/0xeb0 mm/gup.c:1250
 populate_vma_page_range+0x214/0x2b0 mm/gup.c:1607
 __mm_populate+0x248/0x370 mm/gup.c:1721
 mm_populate include/linux/mm.h:2891 [inline]
 vm_mmap_pgoff+0x203/0x2b0 mm/util.c:525
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f551dd8efc9
RSP: 002b:00007f551ec15038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f551dfe6180 RCX: 00007f551dd8efc9
RDX: 000000000000000f RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007f551de11f91 R08: 0000000000000003 R09: 0000000000001000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f551dfe6218 R14: 00007f551dfe6180 R15: 00007ffdb12bc918
 </TASK>
rcu: rcu_preempt kthread starved for 9952 jiffies! g36401 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:27840 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 1 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:741