rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=0c9/1/0x4000000000000000 softirq=9167/9182 fqs=11
(detected by 0, t=10502 jiffies, g=9201, q=350)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5145 Comm: syz.1.277 Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__preempt_count_add kernel/rcu/tree.c:1119 [inline]
RIP: 0010:rcu_is_watching+0x4/0xa0 kernel/rcu/tree.c:1122
Code: 8d 65 e8 5b 41 5e 41 5f 5d c3 e8 f7 80 44 08 41 f7 c7 00 02 00 00 75 b8 eb b7 e8 d7 80 44 08 0f 1f 80 00 00 00 00 41 57 41 56 <53> 65 ff 05 1c c3 9e 7e e8 cf 90 44 08 89 c3 83 f8 08 73 5c 49 bf
RSP: 0018:ffffc90000dd0d08 EFLAGS: 00000002
RAX: ffffffff8167b56a RBX: 0000000000000001 RCX: ffff88805c735940
RDX: 0000000000010000 RSI: 0000000000000001 RDI: 0000000000000002
RBP: ffffc90000dd0e98 R08: dffffc0000000000 R09: fffffbfff1ad2dd6
R10: fffffbfff1ad2dd6 R11: 1ffffffff1ad2dd5 R12: ffff8880b912a290
R13: 1ffff11017225452 R14: 0000000000000001 R15: 0000000000000000
FS: 00007f96871966c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c25d1df CR3: 00000000189b5000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
trace_hrtimer_expire_exit include/trace/events/timer.h:283 [inline]
__run_hrtimer kernel/time/hrtimer.c:1693 [inline]
__hrtimer_run_queues+0x5c3/0xc40 kernel/time/hrtimer.c:1754
hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
__sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa5/0x100 kernel/locking/spinlock.c:194
Code: 74 05 e8 2e 47 cc f7 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 f6 d4 9f f7 65 8b 05 97 d4 50 76 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc900034bee00 EFLAGS: 00000206
RAX: 0c362548ed717500 RBX: 0000000000000a06 RCX: 0c362548ed717500
RDX: dffffc0000000000 RSI: ffffffff8a0b15c0 RDI: 0000000000000001
RBP: ffffc900034bee90 R08: dffffc0000000000 R09: fffffbfff1ff6e32
R10: fffffbfff1ff6e32 R11: 1ffffffff1ff6e31 R12: dffffc0000000000
R13: 00000012738351fc R14: ffff88807ac1b2e8 R15: 1ffff92000697dc0
spin_unlock_irqrestore include/linux/spinlock.h:418 [inline]
taprio_change+0x3ff2/0x4ed0 net/sched/sch_taprio.c:1620
qdisc_create+0x7bd/0x1170 net/sched/sch_api.c:1265
tc_modify_qdisc+0xaa1/0x1770 net/sched/sch_api.c:-1
rtnetlink_rcv_msg+0x9b9/0xe60 net/core/rtnetlink.c:5650
netlink_rcv_skb+0x1e0/0x430 net/netlink/af_netlink.c:2507
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x774/0x920 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x8ab/0xbc0 net/netlink/af_netlink.c:1918
sock_sendmsg_nosec net/socket.c:704 [inline]
__sock_sendmsg net/socket.c:716 [inline]
____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2436
___sys_sendmsg+0x1f0/0x260 net/socket.c:2490
__sys_sendmsg net/socket.c:2519 [inline]
__do_sys_sendmsg net/socket.c:2528 [inline]
__se_sys_sendmsg+0x190/0x250 net/socket.c:2526
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f968932eb69
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:00007f9687196038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f9689555fa0 RCX: 00007f968932eb69
RDX: 0000000000000000 RSI: 00002000000007c0 RDI: 0000000000000004
RBP: 00007f96893b1df1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f9689555fa0 R15: 00007ffe33556658
rcu: rcu_preempt kthread starved for 10479 jiffies! g9201 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
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:28128 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
schedule+0x11b/0x1e0 kernel/sched/core.c:6459
schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 0
CPU: 0 PID: 5148 Comm: syz.2.279 Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
rcu_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487
print_other_cpu_stall+0x10c8/0x1220 kernel/rcu/tree_stall.h:592
check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
rcu_pending kernel/rcu/tree.c:3936 [inline]
rcu_sched_clock_irq+0x831/0x1110 kernel/rcu/tree.c:2619
update_process_times+0x193/0x200 kernel/time/timer.c:1818
tick_sched_handle kernel/time/tick-sched.c:254 [inline]
tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
__run_hrtimer kernel/time/hrtimer.c:1690 [inline]
__hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1754
hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
__sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:csd_lock_wait kernel/smp.c:440 [inline]
RIP: 0010:smp_call_function_many_cond+0xb88/0xd70 kernel/smp.c:969
Code: b6 44 05 00 84 c0 0f 85 9d 00 00 00 41 8b 1c 24 89 de 83 e6 01 31 ff e8 a6 46 0b 00 83 e3 01 75 07 e8 3c 43 0b 00 eb 43 f3 90 <48> b8 00 00 00 00 00 fc ff df 41 0f b6 44 05 00 84 c0 75 11 41 f7
RSP: 0018:ffffc9000347f900 EFLAGS: 00000246
RAX: ffffffff816c810b RBX: 0000000000000001 RCX: 0000000000080000
RDX: ffffc9000f40c000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc9000347fa40 R08: dffffc0000000000 R09: fffffbfff1ff6e2d
R10: fffffbfff1ff6e2d R11: 1ffffffff1ff6e2c R12: ffff8880b9140588
R13: 1ffff110172280b1 R14: ffff8880b903b380 R15: 0000000000000001
on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1135
kill_bdev block/bdev.c:76 [inline]
set_blocksize+0x2eb/0x370 block/bdev.c:157
sb_set_blocksize block/bdev.c:166 [inline]
sb_min_blocksize+0xdc/0x1a0 block/bdev.c:182
ext4_fill_super+0x642/0x9a00 fs/ext4/super.c:3942
mount_bdev+0x287/0x3c0 fs/super.c:1400
legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
vfs_get_tree+0x88/0x270 fs/super.c:1530
do_new_mount+0x24a/0xa40 fs/namespace.c:3014
do_mount fs/namespace.c:3357 [inline]
__do_sys_mount fs/namespace.c:3565 [inline]
__se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3542
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f449c00530a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007f4499e49e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f4499e49ef0 RCX: 00007f449c00530a
RDX: 0000200000000180 RSI: 0000200000000000 RDI: 00007f4499e49eb0
RBP: 0000200000000180 R08: 00007f4499e49ef0 R09: 000000000021081e
R10: 000000000021081e R11: 0000000000000246 R12: 0000200000000000
R13: 00007f4499e49eb0 R14: 000000000000050c R15: 0000200000000240