rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P16787/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=125585, q=172 ncpus=2)
task:syz.2.2541 state:R running task stack:25480 pid:16787 tgid:16781 ppid:5880 task_flags:0x400140 flags:0x20004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288
irqentry_exit+0x6f/0x90 kernel/entry/common.c:197
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 3b f4 02 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc900035f6c98 EFLAGS: 00000206
RAX: a6e6fecc65bd9100 RBX: 0000000000000000 RCX: a6e6fecc65bd9100
RDX: 0000000000000000 RSI: ffffffff8dba6cac RDI: ffffffff8be33680
RBP: ffffffff8172c195 R08: 0000000000000000 R09: ffffffff8172c195
R10: ffffc900035f6e58 R11: ffffffff81ac3820 R12: 0000000000000002
R13: ffffffff8e139ee0 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:330 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:356
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4180 [inline]
slab_alloc_node mm/slub.c:4229 [inline]
kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4236
anon_vma_chain_alloc mm/rmap.c:142 [inline]
anon_vma_clone+0xb8/0x4f0 mm/rmap.c:288
__split_vma+0x351/0xa00 mm/vma.c:535
split_vma mm/vma.c:598 [inline]
vma_modify+0x13b3/0x1970 mm/vma.c:1631
vma_modify_flags+0x1e8/0x230 mm/vma.c:1649
madvise_update_vma mm/madvise.c:169 [inline]
madvise_vma_behavior+0x1ba8/0x3af0 mm/madvise.c:1427
madvise_walk_vmas+0x51c/0xa30 mm/madvise.c:1669
madvise_do_behavior+0x38e/0x550 mm/madvise.c:1885
do_madvise+0x1bc/0x270 mm/madvise.c:1978
__do_sys_madvise mm/madvise.c:1987 [inline]
__se_sys_madvise mm/madvise.c:1985 [inline]
__ia32_sys_madvise+0xa7/0xc0 mm/madvise.c:1985
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
__do_fast_syscall_32+0xb6/0x2b0 arch/x86/entry/syscall_32.c:306
do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7fe3539
RSP: 002b:00000000f54c455c EFLAGS: 00000206 ORIG_RAX: 00000000000000db
RAX: ffffffffffffffda RBX: 0000000080bdd000 RCX: 0000000000002000
RDX: 000000000000000a RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 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 10544 jiffies! g125585 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=81952
rcu: rcu_preempt kthread starved for 10545 jiffies! g125585 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:27160 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 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+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
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: 16794 Comm: syz.3.2543 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__lock_is_held kernel/locking/lockdep.c:5598 [inline]
RIP: 0010:lock_is_held_type+0xba/0x190 kernel/locking/lockdep.c:5940
Code: f0 0a 00 00 45 31 ff 49 83 ff 31 73 24 48 89 df 4c 89 f6 e8 78 02 00 00 85 c0 75 2a 49 ff c7 49 63 85 e8 0a 00 00 48 83 c3 28 <49> 39 c7 7c d8 eb 11 48 c7 c7 b0 b1 00 8e 4c 89 fe e8 30 af 85 f9
RSP: 0018:ffffc90003226fc8 EFLAGS: 00000092
RAX: 0000000000000003 RBX: ffff88804b7d8b40 RCX: ae7e35927e267f00
RDX: ffff88804b7d8000 RSI: ffffffff8e139ee0 RDI: ffff88804b7d8b18
RBP: 00000000ffffffff R08: ffff88804b7d8000 R09: 0000000000000002
R10: 00000000ffffffff R11: 0000000000000002 R12: 0000000000000246
R13: ffff88804b7d8000 R14: ffffffff8e139ee0 R15: 0000000000000002
FS: 0000000000000000(0000) GS:ffff888125d1b000(0063) knlGS:00000000f544eb40
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000800012c0 CR3: 0000000077650000 CR4: 00000000003526f0
Call Trace:
qdisc_lookup_rcu+0x381/0x6d0 net/sched/sch_api.c:333
qdisc_tree_reduce_backlog+0x1b2/0x480 net/sched/sch_api.c:795
fq_codel_change+0x9f6/0xda0 net/sched/sch_fq_codel.c:454
fq_codel_init+0x355/0x960 net/sched/sch_fq_codel.c:489
qdisc_create+0x7ac/0xea0 net/sched/sch_api.c:1319
__tc_modify_qdisc net/sched/sch_api.c:1748 [inline]
tc_modify_qdisc+0x1538/0x20e0 net/sched/sch_api.c:1812
rtnetlink_rcv_msg+0x779/0xb70 net/core/rtnetlink.c:6955
netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2552
netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
netlink_unicast+0x82c/0x9e0 net/netlink/af_netlink.c:1346
netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
sock_sendmsg_nosec net/socket.c:714 [inline]
__sock_sendmsg+0x219/0x270 net/socket.c:729
____sys_sendmsg+0x505/0x830 net/socket.c:2614
___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668
__sys_sendmsg+0x164/0x220 net/socket.c:2700
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
__do_fast_syscall_32+0xb6/0x2b0 arch/x86/entry/syscall_32.c:306
do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf705e539
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:00000000f544e55c EFLAGS: 00000206 ORIG_RAX: 0000000000000172
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000800012c0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000