syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=5304/1/0x4000000000000000 softirq=14661/14662 fqs=2
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P6533/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=9345, q=364 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6549 Comm: syz.4.173 Not tainted 6.14.0-rc7-syzkaller-00196-g88d324e69ea9 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:87 [inline]
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:104 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline]
RIP: 0010:kasan_check_range+0x10e/0x1a0 mm/kasan/generic.c:189
Code: 00 7c 0b 44 89 c2 e8 c1 ec ff ff 83 f0 01 5b 5d 41 5c c3 cc cc cc cc 48 85 d2 74 4f 48 01 ea eb 09 48 83 c0 01 48 39 d0 74 41 <80> 38 00 74 f2 eb b2 41 bc 08 00 00 00 45 29 dc 49 8d 14 2c eb 0c
RSP: 0018:ffffc90000007e10 EFLAGS: 00000082
RAX: fffffbfff20c4d82 RBX: fffffbfff20c4d83 RCX: ffffffff81a7223c
RDX: fffffbfff20c4d83 RSI: 0000000000000008 RDI: ffffffff90626c10
RBP: fffffbfff20c4d82 R08: 0000000000000000 R09: fffffbfff20c4d82
R10: ffffffff90626c17 R11: 0000000000000004 R12: ffff888029276340
R13: ffff8880b862c780 R14: ffff8880b862c680 R15: ffffffff896ae3b0
FS:  00007fea5f7496c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000050808000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 instrument_atomic_read include/linux/instrumented.h:68 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 cpumask_test_cpu include/linux/cpumask.h:570 [inline]
 cpu_online include/linux/cpumask.h:1116 [inline]
 trace_hrtimer_expire_entry include/trace/events/timer.h:259 [inline]
 __run_hrtimer kernel/time/hrtimer.c:1798 [inline]
 __hrtimer_run_queues+0x58c/0xae0 kernel/time/hrtimer.c:1865
 hrtimer_interrupt+0x392/0x8e0 kernel/time/hrtimer.c:1927
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline]
 __sysvec_apic_timer_interrupt+0x10f/0x400 arch/x86/kernel/apic/apic.c:1055
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1049
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:write_comp_data+0x8b/0x90 kernel/kcov.c:272
Code: 00 00 4a 8d 34 dd 28 00 00 00 48 39 f2 72 1b 48 83 c7 01 48 89 38 4c 89 44 30 e0 4c 89 4c 30 e8 4c 89 54 30 f0 4a 89 4c d8 20 <c3> cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3
RSP: 0018:ffffc900035b7760 EFLAGS: 00000297
RAX: 0000000000000002 RBX: ffffea00017c4b80 RCX: ffffffff821a1498
RDX: ffff8880280a0000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900035b7e00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000002 R12: ffff888027352360
R13: 0000000000000000 R14: dffffc0000000000 R15: 00007fea5d06c000
 queue_folios_pte_range+0x498/0x1160 mm/mempolicy.c:576
 walk_pmd_range mm/pagewalk.c:130 [inline]
 walk_pud_range mm/pagewalk.c:226 [inline]
 walk_p4d_range mm/pagewalk.c:264 [inline]
 walk_pgd_range+0xc7b/0x1a70 mm/pagewalk.c:305
 __walk_page_range+0x161/0x820 mm/pagewalk.c:412
 walk_page_range_mm+0x55a/0x940 mm/pagewalk.c:505
 walk_page_range+0x63/0x90 mm/pagewalk.c:584
 queue_pages_range+0xf7/0x180 mm/mempolicy.c:776
 do_mbind+0x444/0xed0 mm/mempolicy.c:1330
 kernel_mbind+0x1e8/0x200 mm/mempolicy.c:1537
 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: 0033:0x7fea5e98d169
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fea5f749038 EFLAGS: 00000246 ORIG_RAX: 00000000000000ed
RAX: ffffffffffffffda RBX: 00007fea5eba5fa0 RCX: 00007fea5e98d169
RDX: 0000000000000000 RSI: 0100000000004000 RDI: 00002000005b4000
RBP: 00007fea5ea0e2a0 R08: 0000000000000000 R09: 0000000000000002
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fea5eba5fa0 R15: 00007fff6c56f7f8
 </TASK>
task:syz.3.167       state:R  running task     stack:26352 pid:6533  tgid:6532  ppid:5820   task_flags:0x40044c flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5378 [inline]
 __schedule+0xf43/0x5890 kernel/sched/core.c:6765
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7087
 irqentry_exit+0x36/0x90 kernel/entry/common.c:354
 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707
RIP: 0010:lock_acquire.part.0+0x155/0x380 kernel/locking/lockdep.c:5816
Code: b8 ff ff ff ff 65 0f c1 05 70 ca 6b 7e 83 f8 01 0f 85 d0 01 00 00 9c 58 f6 c4 02 0f 85 e5 01 00 00 48 85 ed 0f 85 b6 01 00 00 <48> b8 00 00 00 00 00 fc ff df 48 01 c3 48 c7 03 00 00 00 00 48 c7
RSP: 0018:ffffc9000c777450 EFLAGS: 00000206
RAX: 0000000000000046 RBX: 1ffff920018eee8b RCX: 00000000c62827c2
RDX: 0000000000000001 RSI: ffffffff8b6cff80 RDI: ffffffff8bd36a20
RBP: 0000000000000200 R08: 0000000000000000 R09: fffffbfff2dd8d98
R10: ffffffff96ec6cc7 R11: 0000000000000001 R12: 0000000000000000
R13: ffffffff8e1bd140 R14: 0000000000000000 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 rcu_read_lock include/linux/rcupdate.h:849 [inline]
 ___pte_offset_map+0x48/0x540 mm/pgtable-generic.c:287
 __pte_offset_map include/linux/mm.h:3038 [inline]
 __pte_offset_map_lock+0x8e/0x300 mm/pgtable-generic.c:398
 pte_offset_map_lock include/linux/mm.h:3053 [inline]
 zap_pte_range mm/memory.c:1727 [inline]
 zap_pmd_range mm/memory.c:1833 [inline]
 zap_pud_range mm/memory.c:1862 [inline]
 zap_p4d_range mm/memory.c:1883 [inline]
 unmap_page_range+0xa38/0x4390 mm/memory.c:1904
 unmap_single_vma+0x194/0x2b0 mm/memory.c:1950
 unmap_vmas+0x22f/0x490 mm/memory.c:1994
 exit_mmap+0x1c1/0xba0 mm/mmap.c:1284
 __mmput+0x12a/0x410 kernel/fork.c:1356
 mmput+0x62/0x70 kernel/fork.c:1378
 exit_mm kernel/exit.c:570 [inline]
 do_exit+0x9ba/0x2db0 kernel/exit.c:925
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087
 get_signal+0x24ed/0x26c0 kernel/signal.c:3036
 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f569d98d169
RSP: 002b:00007f569e8930e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 00007f569dba5fa8 RCX: 00007f569d98d169
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f569dba5fac
RBP: 00007f569dba5fa0 R08: 00007f569e894000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 00007f569dba5fac
R13: 0000000000000000 R14: 00007ffd4e9346a0 R15: 00007ffd4e934788
 </TASK>
rcu: rcu_preempt kthread starved for 10498 jiffies! g9345 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:27456 pid:18    tgid:18    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5378 [inline]
 __schedule+0xf43/0x5890 kernel/sched/core.c:6765
 __schedule_loop kernel/sched/core.c:6842 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6857
 schedule_timeout+0x124/0x280 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2024
 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2226
 kthread+0x3af/0x750 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 6550 Comm: syz.0.172 Not tainted 6.14.0-rc7-syzkaller-00196-g88d324e69ea9 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline]
RIP: 0010:smp_call_function_many_cond+0x4c6/0x12c0 kernel/smp.c:885
Code: 0c 00 85 ed 74 4d 48 b8 00 00 00 00 00 fc ff df 4d 89 fc 4c 89 fd 49 c1 ec 03 83 e5 07 49 01 c4 83 c5 03 e8 ac 0e 0c 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 e8 0b 00 00 8b 43 08 31
RSP: 0018:ffffc9000f707b28 EFLAGS: 00000246
RAX: 0000000000080000 RBX: ffff8880b8646a00 RCX: ffffc9000c2b9000
RDX: 0000000000080000 RSI: ffffffff81ade1c4 RDI: 0000000000000005
RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000005 R12: ffffed10170c8d41
R13: 0000000000000001 R14: ffff8880b873fe80 R15: ffff8880b8646a08
FS:  00007fc3ea49b6c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc3ea479f98 CR3: 0000000030728000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1052
 on_each_cpu include/linux/smp.h:71 [inline]
 text_poke_sync arch/x86/kernel/alternative.c:2118 [inline]
 text_poke_bp_batch+0x22b/0x760 arch/x86/kernel/alternative.c:2328
 text_poke_flush arch/x86/kernel/alternative.c:2519 [inline]
 text_poke_flush arch/x86/kernel/alternative.c:2516 [inline]
 text_poke_finish+0x30/0x40 arch/x86/kernel/alternative.c:2526
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 jump_label_update+0x1d7/0x400 kernel/jump_label.c:920
 static_key_enable_cpuslocked+0x1b7/0x270 kernel/jump_label.c:210
 static_key_enable+0x1a/0x20 kernel/jump_label.c:223
 __sched_core_enable kernel/sched/core.c:432 [inline]
 sched_core_get+0x8a/0xa0 kernel/sched/core.c:456
 sched_core_alloc_cookie kernel/sched/core_sched.c:18 [inline]
 sched_core_share_pid+0x41f/0xa00 kernel/sched/core_sched.c:185
 __do_sys_prctl+0x971/0x2450 kernel/sys.c:2743
 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: 0033:0x7fc3e958d169
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc3ea49b038 EFLAGS: 00000246 ORIG_RAX: 000000000000009d
RAX: ffffffffffffffda RBX: 00007fc3e97a5fa0 RCX: 00007fc3e958d169
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 000000000000003e
RBP: 00007fc3e960e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fc3e97a5fa0 R15: 00007ffe25f3a318
 </TASK>