rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12395/1:b..l rcu: (detected by 0, t=10502 jiffies, g=77961, q=803 ncpus=2) task:syz.3.1663 state:R running task stack:26592 pid:12395 tgid:12395 ppid:12083 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6529 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6708 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6732 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:1688 [inline] zap_pmd_range mm/memory.c:1736 [inline] zap_pud_range mm/memory.c:1765 [inline] zap_p4d_range mm/memory.c:1786 [inline] unmap_page_range+0x3818/0x42c0 mm/memory.c:1807 unmap_vmas+0x3cc/0x5f0 mm/memory.c:1897 exit_mmap+0x264/0xc80 mm/mmap.c:3382 __mmput+0x115/0x390 kernel/fork.c:1345 exit_mm+0x220/0x310 kernel/exit.c:571 do_exit+0x9b2/0x27f0 kernel/exit.c:869 do_group_exit+0x207/0x2c0 kernel/exit.c:1031 __do_sys_exit_group kernel/exit.c:1042 [inline] __se_sys_exit_group kernel/exit.c:1040 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1040 x64_sys_call+0x26c3/0x26d0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2b3cd75f19 RSP: 002b:00007f2b3d02fd58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f2b3cd75f19 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000006 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2b3d02fe40 R13: 0000000000000000 R14: 0000000000000001 R15: 00007f2b3d02fe40 rcu: rcu_preempt kthread starved for 9402 jiffies! g77961 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:25816 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6621 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2034 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2236 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: cdc_wdm 3-1:1.0: Stall on int endpoint NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 12413 Comm: syz.4.1666 Not tainted 6.10.0-syzkaller-12246-g786c8248dbd3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 RIP: 0010:io_serial_in+0x76/0xb0 drivers/tty/serial/8250/8250_port.c:406 Code: 70 ed 55 fc 89 e9 41 d3 e6 48 83 c3 40 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 b1 38 bd fc 44 03 33 44 89 f2 ec <0f> b6 c0 5b 41 5e 41 5f 5d c3 cc cc cc cc 89 e9 80 e1 07 38 c1 7c RSP: 0018:ffffc90000a176d8 EFLAGS: 00000006 RAX: 1ffffffff2964f05 RBX: ffffffff94b27e40 RCX: 0000000000000000 RDX: 00000000000003f9 RSI: 0000000000000000 RDI: 0000000000000020 RBP: 0000000000000000 R08: ffffffff853d9606 R09: fffff52000142ebc R10: dffffc0000000000 R11: ffffffff853d95c0 R12: dffffc0000000000 R13: ffffffff8eb30aa0 R14: 00000000000003f9 R15: dffffc0000000000 FS: 0000555566882500(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9af44af14c CR3: 0000000070178000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_port_in include/linux/serial_core.h:674 [inline] serial8250_console_write+0x2c2/0x1770 drivers/tty/serial/8250/8250_port.c:3357 console_emit_next_record kernel/printk/printk.c:2983 [inline] console_flush_all+0x865/0xfd0 kernel/printk/printk.c:3049 console_unlock+0x13b/0x4d0 kernel/printk/printk.c:3118 vprintk_emit+0x5a6/0x770 kernel/printk/printk.c:2348 dev_vprintk_emit+0x2ae/0x330 drivers/base/core.c:4909 dev_printk_emit+0xdd/0x120 drivers/base/core.c:4920 _dev_err+0x122/0x170 drivers/base/core.c:4975 wdm_int_callback+0x3d8/0xb30 drivers/usb/class/cdc-wdm.c:266 __usb_hcd_giveback_urb+0x42c/0x6e0 drivers/usb/core/hcd.c:1650 dummy_timer+0x830/0x45a0 drivers/usb/gadget/udc/dummy_hcd.c:1987 __run_hrtimer kernel/time/hrtimer.c:1689 [inline] __hrtimer_run_queues+0x59b/0xd50 kernel/time/hrtimer.c:1753 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1815 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline] __sysvec_apic_timer_interrupt+0x110/0x3f0 arch/x86/kernel/apic/apic.c:1049 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__slab_alloc+0x0/0xa0 mm/slub.c:3801 Code: 4c 89 c6 e8 32 51 ab 09 48 89 d8 5b 41 5e c3 cc cc cc cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <55> 41 57 41 56 41 55 41 54 53 50 44 89 44 24 04 49 89 cf 41 89 d4 RSP: 0018:ffffc90000a187c8 EFLAGS: 00000246 RAX: ffff8880b9500000 RBX: 0000000000000000 RCX: ffffffff89572f68 RDX: 00000000ffffffff RSI: 00000000000a2820 RDI: ffff888018edfa00 RBP: 0000000000000000 R08: 0000000000000280 R09: 00000000000a2820 R10: ffff88805d4a4c80 R11: fffffbfff1f5f4be R12: ffffffff89572f68 R13: ffff888018edfa00 R14: 00000000ffffffff R15: 0000000000000280 __slab_alloc_node mm/slub.c:3866 [inline] slab_alloc_node mm/slub.c:4025 [inline] kmem_cache_alloc_node_noprof+0x1fe/0x320 mm/slub.c:4080 kmalloc_reserve+0xa8/0x2a0 net/core/skbuff.c:583 __alloc_skb+0x1f3/0x440 net/core/skbuff.c:674 __netdev_alloc_skb+0x104/0xa10 net/core/skbuff.c:738 netdev_alloc_skb include/linux/skbuff.h:3348 [inline] dev_alloc_skb include/linux/skbuff.h:3361 [inline] __ieee80211_beacon_get+0x998/0x15c0 net/mac80211/tx.c:5469 ieee80211_beacon_get_tim+0xb4/0x320 net/mac80211/tx.c:5591 ieee80211_beacon_get include/net/mac80211.h:5593 [inline] mac80211_hwsim_beacon_tx+0x39d/0x850 drivers/net/wireless/virtual/mac80211_hwsim.c:2311 __iterate_interfaces+0x223/0x4c0 net/mac80211/util.c:772 ieee80211_iterate_active_interfaces_atomic+0xd8/0x170 net/mac80211/util.c:808 mac80211_hwsim_beacon+0xd4/0x1f0 drivers/net/wireless/virtual/mac80211_hwsim.c:2345 __run_hrtimer kernel/time/hrtimer.c:1689 [inline] __hrtimer_run_queues+0x59b/0xd50 kernel/time/hrtimer.c:1753 hrtimer_run_softirq+0x19a/0x2c0 kernel/time/hrtimer.c:1770 handle_softirqs+0x2c4/0x970 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5763 Code: 2b 00 74 08 4c 89 f7 e8 1a 21 8b 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc90002d17540 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff920005a2eb4 RCX: 84094ec6ec94b100 RDX: dffffc0000000000 RSI: ffffffff8bcae720 RDI: ffffffff8c209de0 RBP: ffffc90002d17688 R08: ffffffff9300289f R09: 1ffffffff2600513 R10: dffffc0000000000 R11: fffffbfff2600514 R12: 1ffff920005a2eb0 R13: dffffc0000000000 R14: ffffc90002d175a0 R15: 0000000000000246 down_read+0xb1/0xa40 kernel/locking/rwsem.c:1526 anon_vma_lock_read include/linux/rmap.h:136 [inline] validate_mm+0x29a/0x530 mm/mmap.c:357 vma_expand+0x802/0xb90 mm/mmap.c:710 mmap_region+0xb9e/0x2090 mm/mmap.c:2900 do_mmap+0x8ad/0xfa0 mm/mmap.c:1438 vm_mmap_pgoff+0x1dd/0x3d0 mm/util.c:588 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f560dd75f53 Code: f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 41 89 ca 41 f7 c1 ff 0f 00 00 75 14 b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 25 c3 0f 1f 40 00 48 c7 c0 a8 ff ff ff 64 c7 RSP: 002b:00007f560e02fa18 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f560c0006c0 RCX: 00007f560dd75f53 RDX: 0000000000000000 RSI: 0000000000021000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 00000000ffffffff R09: 0000000000000000 R10: 0000000000020022 R11: 0000000000000246 R12: 00007f560e02fc70 R13: ffffffffffffffc0 R14: 0000000000001000 R15: 0000000000000000 cdc_wdm 3-1:1.0: Stall on int endpoint cdc_wdm 3-1:1.0: Stall on int endpoint cdc_wdm 3-1:1.0: Stall on int endpoint cdc_wdm 3-1:1.0: Stall on int endpoint cdc_wdm 3-1:1.0: Stall on int endpoint cdc_wdm 3-1:1.0: Stall on int endpoint cdc_wdm 3-1:1.0: Stall on int endpoint cdc_wdm 3-1:1.0: Stall on int endpoint cdc_wdm 3-1:1.0: Stall on int endpoint cdc_wdm 3-1:1.0: Stall on int endpoint cdc_wdm 3-1:1.0: Stall on int endpoint cdc_wdm 3-1:1.0: Stall on int endpoint cdc_wdm 3-1:1.0: Stall on int endpoint cdc_wdm 3-1:1.0: Stall on int endpoint cdc_wdm 3-1:1.0: Stall on int endpoint cdc_wdm 3-1:1.0: Stall on int endpoint cdc_wdm 3-1:1.0: Stall on int endpoint cdc_wdm 3-1:1.0: Stall on int endpoint cdc_wdm 3-1:1.0: nonzero urb status received: -71 cdc_wdm 3-1:1.0: wdm_int_callback - 0 bytes cdc_wdm 3-1:1.0: wdm_int_callback - usb_submit_urb failed with result -1 cdc_wdm 3-1:1.0: Unexpected error -71 cdc_wdm 3-1:1.0: Unexpected error -71