syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P6542/1:b..l
rcu: 	(detected by 0, t=10503 jiffies, g=22085, q=298 ncpus=2)
task:syz-executor.0  state:R  running task     stack:27184 pid:6542  tgid:6541  ppid:5118   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5408 [inline]
 __schedule+0xf15/0x5d00 kernel/sched/core.c:6745
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7067
 irqentry_exit+0x36/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:cpu_max_bits_warn include/linux/cpumask.h:144 [inline]
RIP: 0010:cpumask_check include/linux/cpumask.h:151 [inline]
RIP: 0010:cpumask_test_cpu include/linux/cpumask.h:571 [inline]
RIP: 0010:cpu_online include/linux/cpumask.h:1181 [inline]
RIP: 0010:trace_lock_acquire include/trace/events/lock.h:24 [inline]
RIP: 0010:lock_acquire+0x97/0x560 kernel/locking/lockdep.c:5725
Code: c7 40 0c f3 f3 f3 f3 65 48 8b 04 25 28 00 00 00 48 89 84 24 a8 00 00 00 31 c0 0f 1f 44 00 00 48 c7 c5 4c d9 03 00 65 8b 55 00 <83> fa 07 0f 87 0e 04 00 00 89 d5 be 08 00 00 00 48 89 e8 48 c1 e8
RSP: 0018:ffffc90003517728 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 1ffff920006a2ee7 RCX: 0000000000000002
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffffffff8dbb1920
RBP: 000000000003d94c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000200000 R11: 0000000000000003 R12: 0000000000000000
R13: 0000000000000000 R14: ffffffff8dbb1920 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
 rcu_read_lock include/linux/rcupdate.h:781 [inline]
 avc_has_perm_noaudit+0x67/0x3a0 security/selinux/avc.c:1153
 cred_has_capability security/selinux/hooks.c:1645 [inline]
 selinux_vm_enough_memory+0x12b/0x1b0 security/selinux/hooks.c:2216
 security_vm_enough_memory_mm+0x6d/0xc0 security/security.c:1125
 shmem_acct_blocks mm/shmem.c:200 [inline]
 shmem_inode_acct_blocks+0x345/0x450 mm/shmem.c:216
 shmem_alloc_and_add_folio+0x302/0x790 mm/shmem.c:1693
 shmem_get_folio_gfp+0x687/0x13d0 mm/shmem.c:2055
 shmem_get_folio mm/shmem.c:2160 [inline]
 shmem_write_begin+0x15a/0x360 mm/shmem.c:2743
 generic_perform_write+0x272/0x620 mm/filemap.c:4015
 shmem_file_write_iter+0x114/0x140 mm/shmem.c:2919
 new_sync_write fs/read_write.c:497 [inline]
 vfs_write+0x6b6/0x1140 fs/read_write.c:590
 ksys_write+0x12f/0x260 fs/read_write.c:643
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb950e7bbef
RSP: 002b:00007fb951c4ee80 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00000000013bd7ef RCX: 00007fb950e7bbef
RDX: 00000000013bd7ef RSI: 00007fb946c00000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 00000000000054ed
R10: 00000000000003ce R11: 0000000000000293 R12: 0000000000000003
R13: 00007fb951c4ef80 R14: 00007fb951c4ef40 R15: 00007fb946c00000
 </TASK>
rcu: rcu_preempt kthread starved for 10543 jiffies! g22085 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:27680 pid:17    tgid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5408 [inline]
 __schedule+0xf15/0x5d00 kernel/sched/core.c:6745
 __schedule_loop kernel/sched/core.c:6822 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6837
 schedule_timeout+0x136/0x2a0 kernel/time/timer.c:2581
 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2000
 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2202
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 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 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x1a/0x20 drivers/acpi/processor_idle.c:112
sched: RT throttling activated