rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (1 GPs behind) idle=9a14/1/0x4000000000000000 softirq=0/0 fqs=0 rcuc=10500 jiffies(starved)
rcu: 	(t=10500 jiffies g=44973 q=174 ncpus=2)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g44973 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=43908
rcu: rcu_preempt kthread starved for 10500 jiffies! g44973 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27224 pid:18    tgid:18    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
CPU: 0 UID: 0 PID: 13316 Comm: syz.1.758 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xed4/0x12d0 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 35 60 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 70 5b 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 54 5b
RSP: 0018:ffffc90005987500 EFLAGS: 00000246
RAX: ffffffff81b312bc RBX: 1ffff110171283b1 RCX: 0000000000080000
RDX: ffffc9000d9cb000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90005987680 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1e3ac07 R12: ffff8880b8941d88
R13: dffffc0000000000 R14: ffff8880b883bd00 R15: 0000000000000001
FS:  00007f64f1b2e6c0(0000) GS:ffff8881268bc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f64e974b000 CR3: 00000000356f6000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1044
 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
 flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline]
 flush_tlb_mm_range+0x6b1/0x12d0 arch/x86/mm/tlb.c:1451
 tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
 tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:490 [inline]
 tlb_flush_mmu+0x1a7/0x680 mm/mmu_gather.c:403
 tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:497
 vms_clear_ptes+0x42c/0x540 mm/vma.c:1235
 vms_complete_munmap_vmas+0x206/0x8a0 mm/vma.c:1277
 do_vmi_align_munmap+0x369/0x440 mm/vma.c:1536
 do_vmi_munmap+0x253/0x2e0 mm/vma.c:1584
 __vm_munmap+0x23b/0x3d0 mm/vma.c:3155
 __do_sys_munmap mm/mmap.c:1080 [inline]
 __se_sys_munmap mm/mmap.c:1077 [inline]
 __x64_sys_munmap+0x60/0x70 mm/mmap.c:1077
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f64f38cec37
Code: 00 00 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 0b 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f64f1b2de18 EFLAGS: 00000246 ORIG_RAX: 000000000000000b
RAX: ffffffffffffffda RBX: 0000000000080000 RCX: 00007f64f38cec37
RDX: 0000000000000000 RSI: 0000000008400000 RDI: 00007f64e96cc000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000603
R10: 0000200000000f82 R11: 0000000000000246 R12: 000000000000000a
R13: 00007f64f1b2def0 R14: 00007f64f1b2deb0 R15: 00007f64e96cc000
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 13279 Comm: syz.2.755 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:native_halt+0x18/0x30 arch/x86/include/asm/irqflags.h:55
Code: 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa e8 d7 1e 4c 00 66 90 e8 d0 1e 4c 00 0f 00 2d 79 e4 95 09 f4 <e9> 53 51 88 09 cc f3 0f 1e fa e8 b9 1e 4c 00 f4 e9 43 51 88 09 cc
RSP: 0000:ffffc90004957338 EFLAGS: 00000046
RAX: ffffffff81724f40 RBX: 0000000000000003 RCX: 0000000000080000
RDX: ffffc9000d5ca000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90004957410 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff91ffffb06fb R12: dffffc0000000000
R13: 0000000000000200 R14: 0000000000000003 R15: 1ffff9200092ae6c
FS:  00007fe911d966c0(0000) GS:ffff8881269bc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4c2fc3e000 CR3: 00000000626b8000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 halt arch/x86/include/asm/paravirt.h:112 [inline]
 kvm_wait+0x188/0x290 arch/x86/kernel/kvm.c:1058
 pv_wait arch/x86/include/asm/paravirt.h:569 [inline]
 pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:466 [inline]
 __pv_queued_spin_lock_slowpath+0x7bf/0xb60 kernel/locking/qspinlock.c:325
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:557 [inline]
 queued_spin_lock_slowpath+0x43/0x50 arch/x86/include/asm/qspinlock.h:51
 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
 do_raw_spin_lock+0x21f/0x290 kernel/locking/spinlock_debug.c:116
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
 _raw_spin_lock_irqsave+0xb3/0xf0 kernel/locking/spinlock.c:162
 rtlock_slowlock kernel/locking/rtmutex.c:1894 [inline]
 rtlock_lock kernel/locking/spinlock_rt.c:43 [inline]
 __rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline]
 rt_spin_lock+0x144/0x2c0 kernel/locking/spinlock_rt.c:57
 spin_lock include/linux/spinlock_rt.h:44 [inline]
 do_slab_free mm/slub.c:4662 [inline]
 ___cache_free+0x9b/0x200 mm/slub.c:4753
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_remove_cache+0x16a/0x190 mm/kasan/quarantine.c:378
 kmem_cache_destroy+0x6e/0x160 mm/slab_common.c:521
 bio_put_slab block/bio.c:155 [inline]
 bioset_exit+0x583/0x690 block/bio.c:1764
 __bch2_fs_free fs/bcachefs/super.c:605 [inline]
 bch2_fs_release+0x23c/0x830 fs/bcachefs/super.c:667
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x22b/0x480 lib/kobject.c:737
 bch2_fs_get_tree+0xb6e/0x1520 fs/bcachefs/fs.c:2604
 vfs_get_tree+0x8f/0x2b0 fs/super.c:1815
 do_new_mount+0x2a2/0x9e0 fs/namespace.c:3808
 do_mount fs/namespace.c:4136 [inline]
 __do_sys_mount fs/namespace.c:4347 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4324
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe913b3034a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe911d95e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fe911d95ef0 RCX: 00007fe913b3034a
RDX: 0000200000000040 RSI: 00002000000003c0 RDI: 00007fe911d95eb0
RBP: 0000200000000040 R08: 00007fe911d95ef0 R09: 0000000000000002
R10: 0000000000000002 R11: 0000000000000246 R12: 00002000000003c0
R13: 00007fe911d95eb0 R14: 0000000000005a85 R15: 0000200000000080
 </TASK>
watchdog: BUG: soft lockup - CPU#0 stuck for 225s! [syz.1.758:13316]
Modules linked in:
irq event stamp: 96492
hardirqs last  enabled at (96491): [<ffffffff8af6fbf4>] irqentry_exit+0x74/0x90 kernel/entry/common.c:200
hardirqs last disabled at (96492): [<ffffffff8af6e82e>] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1050
softirqs last  enabled at (29064): [<ffffffff8184dfa4>] __local_bh_enable_ip+0x1a4/0x270 kernel/softirq.c:262
softirqs last disabled at (29058): [<ffffffff89832477>] local_bh_disable include/linux/bottom_half.h:20 [inline]
softirqs last disabled at (29058): [<ffffffff89832477>] spin_lock_bh include/linux/spinlock_rt.h:87 [inline]
softirqs last disabled at (29058): [<ffffffff89832477>] igmp_mcf_get_first+0x1a7/0x3a0 net/ipv4/igmp.c:3006
CPU: 0 UID: 0 PID: 13316 Comm: syz.1.758 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xed4/0x12d0 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 35 60 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 70 5b 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 54 5b
RSP: 0018:ffffc90005987500 EFLAGS: 00000246
RAX: ffffffff81b312bc RBX: 1ffff110171283b1 RCX: 0000000000080000
RDX: ffffc9000d9cb000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90005987680 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1e3ac07 R12: ffff8880b8941d88
R13: dffffc0000000000 R14: ffff8880b883bd00 R15: 0000000000000001
FS:  00007f64f1b2e6c0(0000) GS:ffff8881268bc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f64e974b000 CR3: 00000000356f6000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1044
 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
 flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline]
 flush_tlb_mm_range+0x6b1/0x12d0 arch/x86/mm/tlb.c:1451
 tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
 tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:490 [inline]
 tlb_flush_mmu+0x1a7/0x680 mm/mmu_gather.c:403
 tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:497
 vms_clear_ptes+0x42c/0x540 mm/vma.c:1235
 vms_complete_munmap_vmas+0x206/0x8a0 mm/vma.c:1277
 do_vmi_align_munmap+0x369/0x440 mm/vma.c:1536
 do_vmi_munmap+0x253/0x2e0 mm/vma.c:1584
 __vm_munmap+0x23b/0x3d0 mm/vma.c:3155
 __do_sys_munmap mm/mmap.c:1080 [inline]
 __se_sys_munmap mm/mmap.c:1077 [inline]
 __x64_sys_munmap+0x60/0x70 mm/mmap.c:1077
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f64f38cec37
Code: 00 00 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 0b 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f64f1b2de18 EFLAGS: 00000246 ORIG_RAX: 000000000000000b
RAX: ffffffffffffffda RBX: 0000000000080000 RCX: 00007f64f38cec37
RDX: 0000000000000000 RSI: 0000000008400000 RDI: 00007f64e96cc000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000603
R10: 0000200000000f82 R11: 0000000000000246 R12: 000000000000000a
R13: 00007f64f1b2def0 R14: 00007f64f1b2deb0 R15: 00007f64e96cc000
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 13279 Comm: syz.2.755 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:native_halt+0x18/0x30 arch/x86/include/asm/irqflags.h:55
Code: 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa e8 d7 1e 4c 00 66 90 e8 d0 1e 4c 00 0f 00 2d 79 e4 95 09 f4 <e9> 53 51 88 09 cc f3 0f 1e fa e8 b9 1e 4c 00 f4 e9 43 51 88 09 cc
RSP: 0000:ffffc90004957338 EFLAGS: 00000046
RAX: ffffffff81724f40 RBX: 0000000000000003 RCX: 0000000000080000
RDX: ffffc9000d5ca000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90004957410 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff91ffffb06fb R12: dffffc0000000000
R13: 0000000000000200 R14: 0000000000000003 R15: 1ffff9200092ae6c
FS:  00007fe911d966c0(0000) GS:ffff8881269bc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4c2fc3e000 CR3: 00000000626b8000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 halt arch/x86/include/asm/paravirt.h:112 [inline]
 kvm_wait+0x188/0x290 arch/x86/kernel/kvm.c:1058
 pv_wait arch/x86/include/asm/paravirt.h:569 [inline]
 pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:466 [inline]
 __pv_queued_spin_lock_slowpath+0x7bf/0xb60 kernel/locking/qspinlock.c:325
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:557 [inline]
 queued_spin_lock_slowpath+0x43/0x50 arch/x86/include/asm/qspinlock.h:51
 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
 do_raw_spin_lock+0x21f/0x290 kernel/locking/spinlock_debug.c:116
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
 _raw_spin_lock_irqsave+0xb3/0xf0 kernel/locking/spinlock.c:162
 rtlock_slowlock kernel/locking/rtmutex.c:1894 [inline]
 rtlock_lock kernel/locking/spinlock_rt.c:43 [inline]
 __rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline]
 rt_spin_lock+0x144/0x2c0 kernel/locking/spinlock_rt.c:57
 spin_lock include/linux/spinlock_rt.h:44 [inline]
 do_slab_free mm/slub.c:4662 [inline]
 ___cache_free+0x9b/0x200 mm/slub.c:4753
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_remove_cache+0x16a/0x190 mm/kasan/quarantine.c:378
 kmem_cache_destroy+0x6e/0x160 mm/slab_common.c:521
 bio_put_slab block/bio.c:155 [inline]
 bioset_exit+0x583/0x690 block/bio.c:1764
 __bch2_fs_free fs/bcachefs/super.c:605 [inline]
 bch2_fs_release+0x23c/0x830 fs/bcachefs/super.c:667
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x22b/0x480 lib/kobject.c:737
 bch2_fs_get_tree+0xb6e/0x1520 fs/bcachefs/fs.c:2604
 vfs_get_tree+0x8f/0x2b0 fs/super.c:1815
 do_new_mount+0x2a2/0x9e0 fs/namespace.c:3808
 do_mount fs/namespace.c:4136 [inline]
 __do_sys_mount fs/namespace.c:4347 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4324
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe913b3034a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe911d95e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fe911d95ef0 RCX: 00007fe913b3034a
RDX: 0000200000000040 RSI: 00002000000003c0 RDI: 00007fe911d95eb0
RBP: 0000200000000040 R08: 00007fe911d95ef0 R09: 0000000000000002
R10: 0000000000000002 R11: 0000000000000246 R12: 00002000000003c0
R13: 00007fe911d95eb0 R14: 0000000000005a85 R15: 0000200000000080
 </TASK>