rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8258/1:b..l P8234/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=28297, q=381 ncpus=2)
task:syz.3.344 state:R running task stack:26864 pid:8234 ppid:5763 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6866
preempt_schedule+0xab/0xc0 kernel/sched/core.c:6890
preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3a/0x40 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
zap_pte_range mm/memory.c:1523 [inline]
zap_pmd_range mm/memory.c:1571 [inline]
zap_pud_range mm/memory.c:1600 [inline]
zap_p4d_range mm/memory.c:1621 [inline]
unmap_page_range+0x236f/0x2fe0 mm/memory.c:1642
unmap_vmas+0x25e/0x3a0 mm/memory.c:1732
exit_mmap+0x200/0xb50 mm/mmap.c:3302
__mmput+0x118/0x3c0 kernel/fork.c:1355
exit_mm+0x1da/0x2c0 kernel/exit.c:569
do_exit+0x88e/0x23c0 kernel/exit.c:870
do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
__do_sys_exit_group kernel/exit.c:1035 [inline]
__se_sys_exit_group kernel/exit.c:1033 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fc08898f749
RSP: 002b:00007ffcbabaeea8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc08898f749
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffcbabaef0c R08: 0000001dbabaef9f R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000246 R12: 000000000000005f
R13: 0000000000000000 R14: 0000000000032122 R15: 00007ffcbabaef60
task:rm state:R running task stack:23144 pid:8258 ppid:8215 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7009
irqentry_exit+0x67/0x70 kernel/entry/common.c:438
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
RIP: 0010:atomic_inc include/linux/atomic/atomic-instrumented.h:435 [inline]
RIP: 0010:mt_validate+0x4f0/0x4530 lib/maple_tree.c:7225
Code: 0f 85 34 2e 00 00 e8 ef 7e 30 f7 eb 1d e8 e8 7e 30 f7 48 c7 c7 c0 a8 2a 97 be 04 00 00 00 e8 a7 ee 87 f7 f0 ff 05 d0 96 d5 0c <48> c7 c7 e0 a8 2a 97 be 04 00 00 00 e8 8f ee 87 f7 f0 ff 05 d8 96
RSP: 0018:ffffc9000c687760 EFLAGS: 00000207
RAX: ffffffff8a551101 RBX: 000000000000000e RCX: ffffffff8a5511e9
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff972aa8c0
RBP: ffffc9000c687930 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff2e55518 R12: ffffffffffffffff
R13: 000000000000000e R14: 0000000000000006 R15: dffffc0000000000
validate_mm+0xb1/0x420 mm/mmap.c:288
mmap_region+0xeaa/0x2020 mm/mmap.c:2947
do_mmap+0x92f/0x10a0 mm/mmap.c:1385
vm_mmap_pgoff+0x1c0/0x400 mm/util.c:556
ksys_mmap_pgoff+0x520/0x700 mm/mmap.c:1431
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fc48f281242
RSP: 002b:00007ffd967579c8 EFLAGS: 00000206 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007fc48eef7000 RCX: 00007fc48f281242
RDX: 0000000000000005 RSI: 0000000000037000 RDI: 00007fc48eef7000
RBP: 0000000000000812 R08: 0000000000000003 R09: 0000000000003000
R10: 0000000000000812 R11: 0000000000000206 R12: 00007ffd96757a18
R13: 00007fc48ef606b0 R14: 00007ffd96757e00 R15: 00000fffb2ceaf3c
rcu: rcu_preempt kthread starved for 10562 jiffies! g28297 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:26568 pid:17 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
schedule_timeout+0x160/0x280 kernel/time/timer.c:2168
rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667
rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1866
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 0 Comm: swapper/1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:148
Code: cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d 23 bb 40 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 66 0f 1f 00 55 41 57 41 56
RSP: 0018:ffffc90000187de0 EFLAGS: 000002c2
RAX: 2ca85c10e8d83600 RBX: ffffffff8161881b RCX: 2ca85c10e8d83600
RDX: 0000000000000001 RSI: ffffffff8aaabce0 RDI: ffffffff8afc6f80
RBP: ffffc90000187f20 R08: ffff8880b8f36b2b R09: 1ffff110171e6d65
R10: dffffc0000000000 R11: ffffed10171e6d66 R12: ffffffff8e4a2128
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff1100364e780
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f25d084a000 CR3: 0000000067db4000 CR4: 00000000003506e0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:753
default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97
cpuidle_idle_call kernel/sched/idle.c:170 [inline]
do_idle+0x1eb/0x510 kernel/sched/idle.c:282
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:380
start_secondary+0xee/0xf0 arch/x86/kernel/smpboot.c:323
secondary_startup_64_no_verify+0x179/0x17b