rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P16745/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=95537, q=271 ncpus=2)
task:syz.7.2156 state:R running task stack:25640 pid:16745 ppid:15948 flags:0x00004002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x1553/0x45a0 kernel/sched/core.c:6700
preempt_schedule_irq+0xbf/0x150 kernel/sched/core.c:7010
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:__rcu_read_unlock+0x8/0xd0 kernel/rcu/tree_plugin.h:419
Code: 89 d9 80 e1 07 80 c1 03 38 c1 7c e3 48 89 df e8 7e 93 6d 00 eb d9 66 2e 0f 1f 84 00 00 00 00 00 66 90 f3 0f 1e fa 41 57 41 56 <41> 55 41 54 53 49 bf 00 00 00 00 00 fc ff df 65 48 8b 3d 31 0d 92
RSP: 0018:ffffc9000bfff8b0 EFLAGS: 00000246
RAX: ffffffff81ca9971 RBX: 0000000000000001 RCX: 0000000000080000
RDX: ffffc9001df7e000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc9000bfffaa0 R08: ffff888025a48483 R09: 1ffff11004b49090
R10: dffffc0000000000 R11: ffffed1004b49091 R12: 1ffff920017fff4b
R13: ffffc9000bfffa40 R14: ffffea000100ea00 R15: 0000000000000000
rcu_read_unlock include/linux/rcupdate.h:818 [inline]
pte_unmap include/linux/pgtable.h:113 [inline]
finish_fault+0x8f5/0xc90 mm/memory.c:4508
do_read_fault mm/memory.c:4642 [inline]
do_fault mm/memory.c:4775 [inline]
do_pte_missing mm/memory.c:3689 [inline]
handle_pte_fault mm/memory.c:5047 [inline]
__handle_mm_fault mm/memory.c:5188 [inline]
handle_mm_fault+0x22c1/0x4c00 mm/memory.c:5353
faultin_page mm/gup.c:868 [inline]
__get_user_pages+0x5d0/0x1380 mm/gup.c:1167
populate_vma_page_range+0x2c1/0x380 mm/gup.c:1593
__mm_populate+0x260/0x390 mm/gup.c:1696
mm_populate include/linux/mm.h:3383 [inline]
vm_mmap_pgoff+0x2da/0x3f0 mm/util.c:561
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fd970f9aeb9
RSP: 002b:00007fd971e01028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007fd971215fa0 RCX: 00007fd970f9aeb9
RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007fd971008c1f R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd971216038 R14: 00007fd971215fa0 R15: 00007ffd03916608
</TASK>
rcu: rcu_preempt kthread starved for 10536 jiffies! g95537 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:27656 pid:17 ppid:2 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x1553/0x45a0 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168
rcu_gp_fqs_loop+0x313/0x1590 kernel/rcu/tree.c:1667
rcu_gp_kthread+0x9d/0x3b0 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
</TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 PID: 16753 Comm: syz.3.2158 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:lock_acquire+0x208/0x420 kernel/locking/lockdep.c:5758
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3c 04 f8 0f 85 f0 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 3c 00 00 00 00 43 c7 44 3c 08 00 00 00 00 65 48 8b 04 25
RSP: 0018:ffffc9000bd47780 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: b9f8844d10e7c500
RDX: 0000000000000000 RSI: ffffffff8acada80 RDI: ffffffff8b1c81e0
RBP: ffffc9000bd47890 R08: dffffc0000000000 R09: 1ffffffff2237ea6
R10: dffffc0000000000 R11: fffffbfff2237ea7 R12: 1ffff920017a8efc
R13: ffff888031f9ea20 R14: 0000000000000246 R15: dffffc0000000000
FS: 00007f73a570f6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000058 CR3: 000000005c607000 CR4: 00000000003506e0
Call Trace:
<TASK>
__might_fault+0xc6/0x120 mm/memory.c:5968
__clear_user arch/x86/include/asm/uaccess_64.h:167 [inline]
copy_fpstate_to_sigframe+0x154/0xc60 arch/x86/kernel/fpu/signal.c:216
get_sigframe+0x5e2/0x7d0 arch/x86/kernel/signal.c:142
x64_setup_rt_frame+0x15e/0xc40 arch/x86/kernel/signal_64.c:175
setup_rt_frame arch/x86/kernel/signal.c:223 [inline]
handle_signal arch/x86/kernel/signal.c:267 [inline]
arch_do_signal_or_restart+0x42c/0x800 arch/x86/kernel/signal.c:312
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f73a479aeb7
Code: 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89
RSP: 002b:00007f73a570f0e8 EFLAGS: 00000246
RAX: 00000000000000ca RBX: 00007f73a4a16098 RCX: 00007f73a479aeb9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f73a4a16098
RBP: 00007f73a4a16090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f73a4a16128 R14: 00007ffc696fbad0 R15: 00007ffc696fbbb8
</TASK>