rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P31722/1:b..l P12466/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=369253, q=193 ncpus=2)
task:syz.8.12764 state:R running task stack:26752 pid:12466 tgid:12462 ppid:4380 task_flags:0x400040 flags:0x10080000
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0x14ea/0x5050 kernel/sched/core.c:6867
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7194
irqentry_exit+0x597/0x620 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:58 [inline]
RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:409 [inline]
RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:419 [inline]
RIP: 0010:unwind_next_frame+0xd5f/0x23c0 arch/x86/kernel/unwind_orc.c:600
Code: 8d 5c 24 f8 4d 8b 66 10 48 b8 00 00 00 00 00 fc ff df 48 8b 4c 24 20 0f b6 04 01 84 c0 0f 85 51 11 00 00 41 83 3e 00 0f 95 c0 <49> 39 df 0f 96 c1 20 c1 49 39 dc 0f 97 c0 20 c8 3c 01 75 18 48 8d
RSP: 0000:ffffc9000d467498 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffc9000d4679a0 RCX: 1ffff92001a8cead
RDX: ffffffff90b7891c RSI: 0000000000000002 RDI: ffffffff8c0739a0
RBP: 1ffff92001a8ceae R08: 0000000000000008 R09: ffffffff8e55a360
R10: ffffc9000d4675b8 R11: ffffffff81afb170 R12: ffffc9000d468000
R13: 1ffff92001a8ceaf R14: ffffc9000d467568 R15: ffffc9000d460000
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2540 [inline]
slab_free mm/slub.c:6674 [inline]
kfree+0x1be/0x650 mm/slub.c:6882
io_clean_op+0x298/0x330 io_uring/io_uring.c:384
io_free_batch_list io_uring/io_uring.c:1500 [inline]
__io_submit_flush_completions+0xd88/0xfb0 io_uring/io_uring.c:1538
io_submit_flush_completions io_uring/io_uring.h:239 [inline]
io_submit_state_end io_uring/io_uring.c:2335 [inline]
io_submit_sqes+0x1c26/0x2130 io_uring/io_uring.c:2450
__do_sys_io_uring_enter io_uring/io_uring.c:3285 [inline]
__se_sys_io_uring_enter+0x2f7/0x2c30 io_uring/io_uring.c:3224
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
__do_fast_syscall_32+0x1d2/0x540 arch/x86/entry/syscall_32.c:307
do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7ff5539
RSP: 002b:00000000f547450c EFLAGS: 00000206 ORIG_RAX: 00000000000001aa
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00000000000047bc
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
task:syz-executor state:R running task stack:22168 pid:31722 tgid:31722 ppid:31707 task_flags:0x400140 flags:0x10080000
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0x14ea/0x5050 kernel/sched/core.c:6867
preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7051
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
copy_pte_range mm/memory.c:1331 [inline]
copy_pmd_range+0x7586/0x8030 mm/memory.c:1392
copy_pud_range mm/memory.c:1429 [inline]
copy_p4d_range mm/memory.c:1453 [inline]
copy_page_range+0xb8d/0x11c0 mm/memory.c:1539
dup_mmap+0xf70/0x1bb0 mm/mmap.c:1827
dup_mm kernel/fork.c:1529 [inline]
copy_mm+0x13b/0x4b0 kernel/fork.c:1581
copy_process+0x166e/0x3980 kernel/fork.c:2221
kernel_clone+0x248/0x870 kernel/fork.c:2651
__do_compat_sys_ia32_clone arch/x86/kernel/sys_ia32.c:254 [inline]
__se_compat_sys_ia32_clone arch/x86/kernel/sys_ia32.c:240 [inline]
__ia32_compat_sys_ia32_clone+0x1b4/0x230 arch/x86/kernel/sys_ia32.c:240
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
__do_fast_syscall_32+0x1d2/0x540 arch/x86/entry/syscall_32.c:307
do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf73cd539
RSP: 002b:00000000f751fc80 EFLAGS: 00000206 ORIG_RAX: 0000000000000078
RAX: ffffffffffffffda RBX: 0000000001200011 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000569c24e8
RBP: 00000000f751fcb4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g369253 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=140913
rcu: rcu_preempt kthread starved for 10502 jiffies! g369253 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:28000 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0x14ea/0x5050 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
schedule+0x164/0x360 kernel/sched/core.c:6964
schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x312/0x1560 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:2285
kthread+0x726/0x8b0 kernel/kthread.c:463
ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 12468 Comm: syz.5.12765 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:num_possible_cpus include/linux/cpumask.h:1222 [inline]
RIP: 0010:mm_get_cid kernel/sched/sched.h:3782 [inline]
RIP: 0010:sched_mm_cid_fork+0x2f6/0xc20 kernel/sched/core.c:10582
Code: 01 00 00 85 ed 0f 84 0b 01 00 00 31 ed 31 db e9 c1 01 00 00 49 c7 c5 c8 b4 f7 8d 49 c1 ed 03 eb 07 44 89 e0 f7 d8 71 8d f3 90 <48> b8 00 00 00 00 00 fc ff df 41 0f b6 44 05 00 84 c0 75 50 44 8b
RSP: 0018:ffffc9000e897c78 EFLAGS: 00000887
RAX: 0000000080000000 RBX: 0000000000000002 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffff88807c21d510
RBP: ffff88807c21d510 R08: 1ffff1100f843951 R09: ffff88807c21cbd4
R10: ffff88807c21ca90 R11: fffff52001d12f80 R12: 0000000080000000
R13: 1ffffffff1bef699 R14: 0000000000000002 R15: ffff88807c21c980
FS: 0000000000000000(0000) GS:ffff8881257f5000(0063) knlGS:00000000f54a6b40
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f7f255b8 CR3: 0000000048828000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
bprm_execve+0xda1/0x1410 fs/exec.c:1776
do_execveat_common+0x50f/0x690 fs/exec.c:1859
compat_do_execveat fs/exec.c:1976 [inline]
__do_compat_sys_execveat fs/exec.c:2037 [inline]
__se_compat_sys_execveat fs/exec.c:2031 [inline]
__ia32_compat_sys_execveat+0xca/0xe0 fs/exec.c:2031
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
do_int80_emulation+0x111/0x400 arch/x86/entry/syscall_32.c:172
asm_int80_emulation+0x1a/0x20 arch/x86/include/asm/idtentry.h:621
RIP: 0023:0xf747d539
Code: 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f54a650c EFLAGS: 00000206 ORIG_RAX: 0000000000000166
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000080000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000001000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000