syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P7383/1:b..l P19852/1:b..l
rcu: 	(detected by 0, t=10503 jiffies, g=73689, q=27 ncpus=2)
task:vhost-19851     state:R  running task     stack:27680 pid:19852 ppid:5061   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0xee1/0x5a10 kernel/sched/core.c:6695
 preempt_schedule_irq+0x52/0x90 kernel/sched/core.c:7007
 irqentry_exit+0x35/0x80 kernel/entry/common.c:432
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645
RIP: 0010:__sanitizer_cov_trace_pc+0x3b/0x70 kernel/kcov.c:207
Code: 81 e1 00 01 00 00 65 48 8b 14 25 c0 bc 03 00 a9 00 01 ff 00 74 0e 85 c9 74 35 8b 82 04 16 00 00 85 c0 74 2b 8b 82 e0 15 00 00 <83> f8 02 75 20 48 8b 8a e8 15 00 00 8b 92 e4 15 00 00 48 8b 01 48
RSP: 0018:ffffc90015797400 EFLAGS: 00000246
RAX: 0000000000000002 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff8880432e1dc0 RSI: ffffffff8a2c283d RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001
R13: ffff88807db3e8c0 R14: 0000000000000000 R15: 000000001fffefff
 mt_external_lock include/linux/maple_tree.h:604 [inline]
 mt_locked lib/maple_tree.c:805 [inline]
 mt_slot lib/maple_tree.c:812 [inline]
 mtree_range_walk+0x53d/0x9b0 lib/maple_tree.c:2827
 mas_state_walk lib/maple_tree.c:3712 [inline]
 mt_find+0x4c3/0x990 lib/maple_tree.c:6531
 find_vma+0x10e/0x1b0 mm/mmap.c:1877
 gup_vma_lookup+0x24/0x220 mm/gup.c:1105
 __get_user_pages+0x29a/0x1480 mm/gup.c:1207
 __get_user_pages_locked mm/gup.c:1504 [inline]
 __gup_longterm_locked+0x755/0x2570 mm/gup.c:2198
 internal_get_user_pages_fast+0x1aca/0x2a10 mm/gup.c:3203
 pin_user_pages_fast+0xa8/0xf0 mm/gup.c:3309
 set_bit_to_user drivers/vhost/vhost.c:2126 [inline]
 log_write+0x238/0x2d0 drivers/vhost/vhost.c:2152
 log_used.isra.0+0x170/0x1e0 drivers/vhost/vhost.c:2208
 vhost_update_used_flags+0x30d/0x3e0 drivers/vhost/vhost.c:2271
 vhost_enable_notify+0xd2/0xa30 drivers/vhost/vhost.c:2818
 vhost_vsock_handle_tx_kick+0x8a5/0xbe0 drivers/vhost/vsock.c:501
 vhost_worker+0x17e/0x200 drivers/vhost/vhost.c:411
 vhost_task_fn+0x16a/0x370 kernel/vhost_task.c:55
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
 </TASK>
task:kworker/u4:17   state:R  running task     stack:23552 pid:7383  ppid:2      flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0xee1/0x5a10 kernel/sched/core.c:6695
 preempt_schedule_irq+0x52/0x90 kernel/sched/core.c:7007
 irqentry_exit+0x35/0x80 kernel/entry/common.c:432
 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:650
RIP: 0010:rcu_read_lock include/linux/rcupdate.h:750 [inline]
RIP: 0010:batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
RIP: 0010:batadv_nc_worker+0xc84/0x10e0 net/batman-adv/network-coding.c:719
Code: f7 48 c7 c2 80 2e cd 8b be 0a 03 00 00 48 c7 c7 40 2e cd 8b c6 05 88 c1 ae 04 01 e8 46 1a 60 f7 e9 54 fc ff ff e8 2c 33 80 f7 <e8> a7 c7 68 f7 31 ff 41 89 c7 89 c6 e8 4b 2e 80 f7 45 84 ff 0f 85
RSP: 0018:ffffc90015487bb8 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff888029749c00 RCX: 0000000000000000
RDX: ffff88807b1c8000 RSI: ffffffff8a07a704 RDI: 0000000000000005
RBP: 0000000000000380 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 1ffffffff1976cc1 R12: ffff88807c590ec0
R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000001
 process_one_work+0x884/0x15c0 kernel/workqueue.c:2630
 process_scheduled_works kernel/workqueue.c:2703 [inline]
 worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784
 kthread+0x33c/0x440 kernel/kthread.c:388
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
 </TASK>
rcu: rcu_preempt kthread starved for 10565 jiffies! g73689 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:28656 pid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0xee1/0x5a10 kernel/sched/core.c:6695
 schedule+0xe7/0x1b0 kernel/sched/core.c:6771
 schedule_timeout+0x157/0x2c0 kernel/time/timer.c:2167
 rcu_gp_fqs_loop+0x1ec/0xa50 kernel/rcu/tree.c:1613
 rcu_gp_kthread+0x249/0x380 kernel/rcu/tree.c:1812
 kthread+0x33c/0x440 kernel/kthread.c:388
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 PID: 19869 Comm: syz-executor.2 Not tainted 6.6.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202
Code: 90 f3 0f 1e fa 53 48 8b 74 24 08 48 89 fb 48 83 c7 18 e8 da 03 27 f7 48 89 df e8 d2 82 27 f7 e8 8d fd 4c f7 fb bf 01 00 00 00 <e8> b2 e7 18 f7 65 8b 05 43 2a c2 75 85 c0 74 02 5b c3 e8 50 ef be
RSP: 0018:ffffc90015f47d00 EFLAGS: 00000202
RAX: 0000000003add201 RBX: ffff888042f20940 RCX: 1ffffffff1d97dd1
RDX: 0000000000000000 RSI: ffffffff8a8cac80 RDI: 0000000000000001
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff8ecc2017 R11: 0000000000000000 R12: ffff888042f20dd8
R13: 0000000000000021 R14: ffff888042f20d40 R15: 1ffff92002be8faf
FS:  00007fd02c0956c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd02c094ec0 CR3: 0000000024e5f000 CR4: 0000000000350ef0
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 spin_unlock_irq include/linux/spinlock.h:401 [inline]
 get_signal+0x1899/0x2790 kernel/signal.c:2895
 arch_do_signal_or_restart+0x90/0x7f0 arch/x86/kernel/signal.c:309
 exit_to_user_mode_loop kernel/entry/common.c:168 [inline]
 exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x1d/0x60 kernel/entry/common.c:296
 do_syscall_64+0x44/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fffa6f9ea14
Code: c9 d3 e0 89 c2 81 e2 83 08 00 00 0f 84 c2 00 00 00 41 8b 3a 40 f6 c7 01 0f 85 a0 00 00 00 41 8b 42 04 83 f8 01 75 7f 0f 01 f9 <66> 90 48 c1 e2 20 48 09 c2 48 0f ba f2 3f 49 2b 52 08 4d 63 c1 49
RSP: 002b:00007fd02c0950b8 EFLAGS: 00000246
RAX: 0000000024968274 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 000000000000035b RSI: 00007fd02c095140 RDI: 000000000004dfdc
RBP: 00007fd02c0950d0 R08: 0000000000000000 R09: 0000000000000001
R10: 00007fffa6f9a080 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fd02b39bf80 R15: 00007fffa6e8d618
 </TASK>