syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P10649/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=63377, q=96 ncpus=2)
task:syz-executor.0  state:R  running task     stack:25680 pid:10649 tgid:10643 ppid:5111   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5408 [inline]
 __schedule+0xf15/0x5d00 kernel/sched/core.c:6745
 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6924
 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12
 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 zap_pte_range mm/memory.c:1676 [inline]
 zap_pmd_range mm/memory.c:1724 [inline]
 zap_pud_range mm/memory.c:1753 [inline]
 zap_p4d_range mm/memory.c:1774 [inline]
 unmap_page_range+0xbc7/0x3f20 mm/memory.c:1795
 unmap_single_vma+0x194/0x2b0 mm/memory.c:1841
 unmap_vmas+0x22f/0x490 mm/memory.c:1885
 exit_mmap+0x1b8/0xb20 mm/mmap.c:3341
 __mmput+0x12a/0x4d0 kernel/fork.c:1346
 mmput+0x62/0x70 kernel/fork.c:1368
 exit_mm kernel/exit.c:565 [inline]
 do_exit+0x9b7/0x2ba0 kernel/exit.c:861
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1023
 get_signal+0x2616/0x2710 kernel/signal.c:2909
 arch_do_signal_or_restart+0x90/0x7e0 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+0x14a/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f940367d0a9
RSP: 002b:00007f94031ff0c8 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: 0000000000010106 RBX: 00007f94037b4050 RCX: 00007f940367d0a9
RDX: 0000000000010106 RSI: 00000000200000c0 RDI: 0000000000000005
RBP: 00007f94036ec074 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007f94037b4050 R15: 00007ffe5173a7b8
 </TASK>
rcu: rcu_preempt kthread starved for 10524 jiffies! g63377 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: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:
CPU: 0 PID: 10688 Comm: syz-executor.4 Not tainted 6.10.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
RIP: 0010:finish_task_switch.isra.0+0x220/0xcc0 kernel/sched/core.c:5282
Code: a9 0a 00 00 44 8b 0d 37 27 86 0e 45 85 c9 0f 85 c0 01 00 00 48 89 df e8 ae f8 ff ff e8 69 db 36 00 fb 65 48 8b 1d 40 89 a5 7e <48> 8d bb f8 15 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1
RSP: 0018:ffffc900032ef9d0 EFLAGS: 00000206
RAX: 00000000005f0fb7 RBX: ffff88805c7f5a00 RCX: 1ffffffff1fc8031
RDX: 0000000000000000 RSI: ffffffff8b2caf40 RDI: ffffffff8b8ff940
RBP: ffffc900032efa18 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff8fe44417 R11: 0000000000000000 R12: ffff8880b923f938
R13: ffff88805c7f3c00 R14: 0000000000000000 R15: ffff8880b923ebc0
FS:  00007f3d84bbf6c0(0000) GS:ffff8880b9200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32c2a000 CR3: 000000005ce88000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 context_switch kernel/sched/core.c:5411 [inline]
 __schedule+0xf1d/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:constant_test_bit arch/x86/include/asm/bitops.h:206 [inline]
RIP: 0010:arch_test_bit arch/x86/include/asm/bitops.h:238 [inline]
RIP: 0010:tif_need_resched include/linux/thread_info.h:184 [inline]
RIP: 0010:need_resched include/linux/sched.h:2110 [inline]
RIP: 0010:preempt_schedule_common+0x4b/0xc0 kernel/sched/core.c:6932
Code: c3 65 ff 05 df 36 1a 75 65 8b 05 d8 36 1a 75 25 ff ff ff 7f 83 f8 01 74 29 bf 01 00 00 00 e8 8c 9d ff ff 65 ff 0d bd 36 1a 75 <80> 3b 00 75 5f 48 8b 45 00 a8 08 75 ca 5b 5d 41 5c 41 5d c3 cc cc
RSP: 0018:ffffc900032efc98 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffed100b8feb40 RCX: fffff5200065df74
RDX: 1ffff1100b8fee0b RSI: ffffffff8b2caf40 RDI: ffff88805c7f7058
RBP: ffff88805c7f5a00 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff8fe44417 R11: 0000000000000000 R12: ffffffff8100a13a
R13: ffff88805c7f5a00 R14: 0000000000000200 R15: ffffffff81654eb0
 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12
 __sched_setscheduler.constprop.0+0xe8a/0x2a80 kernel/sched/core.c:7923
 _sched_setscheduler kernel/sched/core.c:7950 [inline]
 sched_setscheduler kernel/sched/core.c:7967 [inline]
 do_sched_setscheduler+0x128/0x240 kernel/sched/core.c:8059
 __do_sys_sched_setscheduler kernel/sched/core.c:8130 [inline]
 __se_sys_sched_setscheduler kernel/sched/core.c:8125 [inline]
 __x64_sys_sched_setscheduler+0x75/0xa0 kernel/sched/core.c:8125
 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: 0033:0x7f3d83e7d0a9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3d84bbf0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000090
RAX: ffffffffffffffda RBX: 00007f3d83fb4120 RCX: 00007f3d83e7d0a9
RDX: 0000000020000200 RSI: 0000000000000002 RDI: 0000000000000000
RBP: 00007f3d83eec074 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007f3d83fb4120 R15: 00007ffe33d91c38
 </TASK>