syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P7756/1:b..l
rcu: 	(detected by 1, t=10503 jiffies, g=39065, q=641 ncpus=2)
task:syz-executor.1  state:R  running task     stack:25040 pid:7756  tgid:7740  ppid:7180   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5409 [inline]
 __schedule+0x17e8/0x4a50 kernel/sched/core.c:6746
 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7068
 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354
 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707
RIP: 0010:memset+0xf/0x20 arch/x86/lib/memset_64.S:37
Code: 44 88 1f e9 1e cb 2f 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 49 89 f9 40 88 f0 48 89 d1 <f3> aa 4c 89 c8 e9 f2 ca 2f 00 0f 1f 80 00 00 00 00 90 90 90 90 90
RSP: 0018:ffffc90014aded50 EFLAGS: 00000202
RAX: ffffffff81416f00 RBX: ffff8880271f0000 RCX: 000000000000005f
RDX: 0000000000000060 RSI: 0000000000000000 RDI: ffffc90014adedc1
RBP: dffffc0000000000 R08: ffffc90014adee1f R09: ffffc90014adedc0
R10: dffffc0000000000 R11: fffff5200295bdc4 R12: 0000000000000000
R13: ffffffff8181e7c0 R14: ffffc90014adedc0 R15: 0000000000000000
 __unwind_start+0x3e/0x7c0 arch/x86/kernel/unwind_orc.c:688
 unwind_start arch/x86/include/asm/unwind.h:64 [inline]
 arch_stack_walk+0x103/0x1b0 arch/x86/kernel/stacktrace.c:24
 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122
 save_stack+0xfb/0x1f0 mm/page_owner.c:156
 __reset_page_owner+0x75/0x3f0 mm/page_owner.c:302
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1141 [inline]
 free_unref_page_prepare+0x986/0xab0 mm/page_alloc.c:2347
 free_unref_folios+0x1f2/0xc10 mm/page_alloc.c:2536
 folios_put_refs+0x93a/0xa60 mm/swap.c:1034
 folio_batch_release include/linux/pagevec.h:101 [inline]
 shmem_undo_range+0x6d9/0x1df0 mm/shmem.c:1005
 shmem_truncate_range mm/shmem.c:1114 [inline]
 shmem_evict_inode+0x29b/0xa60 mm/shmem.c:1242
 evict+0x2aa/0x630 fs/inode.c:667
 __dentry_kill+0x20d/0x630 fs/dcache.c:603
 dput+0x19f/0x2b0 fs/dcache.c:845
 __fput+0x678/0x8a0 fs/file_table.c:430
 task_work_run+0x251/0x310 kernel/task_work.c:180
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0xa1b/0x27e0 kernel/exit.c:878
 do_group_exit+0x207/0x2c0 kernel/exit.c:1027
 get_signal+0x16a1/0x1740 kernel/signal.c:2911
 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218
 do_syscall_64+0x102/0x240 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f395947dd69
RSP: 002b:00007f395a14e0c8 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: 0000000000010106 RBX: 00007f39595ac050 RCX: 00007f395947dd69
RDX: 0000000000010106 RSI: 00000000200000c0 RDI: 0000000000000003
RBP: 00007f39594ca49e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007f39595ac050 R15: 00007ffd0d2c4d48
 </TASK>
rcu: rcu_preempt kthread starved for 10560 jiffies! g39065 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:25616 pid:16    tgid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5409 [inline]
 __schedule+0x17e8/0x4a50 kernel/sched/core.c:6746
 __schedule_loop kernel/sched/core.c:6823 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6838
 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2582
 rcu_gp_fqs_loop+0x2df/0x1370 kernel/rcu/tree.c:1663
 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:1862
 kthread+0x2f2/0x390 kernel/kthread.c:388
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 7789 Comm: syz-executor.5 Not tainted 6.9.0-rc7-syzkaller-00136-gf4345f05c0df #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:check_preemption_disabled+0x67/0x120 lib/smp_processor_id.c:19
Code: 85 ce 00 00 00 89 d8 48 83 c4 10 5b 41 5c 41 5e 41 5f e9 87 d5 2f 00 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 <74> c5 49 89 f6 49 89 ff 65 4c 8b 24 25 c0 d3 03 00 41 f6 44 24 2f
RSP: 0018:ffffc900097f7bc8 EFLAGS: 00000046
RAX: 0000000080000000 RBX: 0000000000000000 RCX: ffffffff81728544
RDX: 0000000000000000 RSI: ffffffff8bcac580 RDI: ffffffff8c1f8260
RBP: ffffc900097f7d58 R08: ffffffff8fa8fa2f R09: 1ffffffff1f51f45
R10: dffffc0000000000 R11: fffffbfff1f51f46 R12: 1ffff920012fef88
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000246
FS:  00007ff54ac216c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33523000 CR3: 0000000078e5e000 CR4: 0000000000350ef0
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 lockdep_recursion_inc kernel/locking/lockdep.c:462 [inline]
 lock_acquire+0x1b0/0x550 kernel/locking/lockdep.c:5753
 __might_fault+0xc6/0x120 mm/memory.c:6220
 rseq_get_rseq_cs kernel/rseq.c:161 [inline]
 rseq_ip_fixup kernel/rseq.c:281 [inline]
 __rseq_handle_notify_resume+0x120/0x14e0 kernel/rseq.c:329
 rseq_handle_notify_resume include/linux/rseq.h:38 [inline]
 resume_user_mode_work include/linux/resume_user_mode.h:62 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x114/0x370 kernel/entry/common.c:218
 do_syscall_64+0x102/0x240 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff549ea54f0
Code: 83 c0 16 83 e0 f7 74 12 50 48 8d 3d da 9c 04 00 e8 15 78 fa ff 0f 1f 44 00 00 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 <83> ff 21 74 0b c3 66 2e 0f 1f 84 00 00 00 00 00 55 53 48 89 f3 48
RSP: 002b:00007ff54ac20bb8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000000 RBX: 00007ff549fac058 RCX: 00007ff549e7dd69
RDX: 00007ff54ac20bc0 RSI: 00007ff54ac20cf0 RDI: 0000000000000021
RBP: 00007ff549fac050 R08: 00007ff54ac216c0 R09: 00007ff54ac216c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ff549fac05c
R13: 000000000000006e R14: 00007ffc8e2c2fb0 R15: 00007ffc8e2c3098
 </TASK>