rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 1-...!: (10563 ticks this GP) idle=292c/1/0x4000000000000000 softirq=84338/84340 fqs=411
(t=10500 jiffies g=125781 q=346 ncpus=2)
rcu: rcu_preempt kthread starved for 9659 jiffies! g125781 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:27760 pid:16 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
schedule+0xb9/0x180 kernel/sched/core.c:6638
schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168
rcu_gp_fqs_loop+0x303/0x1340 kernel/rcu/tree.c:1706
rcu_gp_kthread+0x99/0x3b0 kernel/rcu/tree.c:1905
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:hsr_xmit net/hsr/hsr_forward.c:380 [inline]
RIP: 0010:hsr_forward_do net/hsr/hsr_forward.c:473 [inline]
RIP: 0010:hsr_forward_skb+0x11d0/0x20f0 net/hsr/hsr_forward.c:626
Code: 74 24 38 74 0e 4c 89 f7 49 89 d4 e8 5a a4 c8 f7 4c 89 e2 4d 8b 36 b8 80 03 00 00 49 01 c6 4c 89 f0 48 c1 e8 03 42 80 3c 28 00 <74> 0e 4c 89 f7 49 89 d4 e8 33 a4 c8 f7 4c 89 e2 4d 8b 26 4c 89 e0
RSP: 0018:ffffc90000007900 EFLAGS: 00000246
RAX: 1ffff1100f2f2c70 RBX: ffff8880563a9c00 RCX: dffffc0000000000
RDX: 0000000000000042 RSI: 0000000000000042 RDI: 000000000000ffff
RBP: ffffc90000007a48 R08: ffff8880563a9ce3 R09: 1ffff1100ac7539c
R10: dffffc0000000000 R11: ffffed100ac7539d R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff888079796380 R15: ffff88802746aa80
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fddfaa7175b CR3: 000000001e3c2000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
send_hsr_supervision_frame+0x5f7/0xb80 net/hsr/hsr_device.c:346
hsr_announce+0x194/0x340 net/hsr/hsr_device.c:402
call_timer_fn+0x1ac/0x670 kernel/time/timer.c:1701
expire_timers kernel/time/timer.c:1752 [inline]
__run_timers+0x53e/0x800 kernel/time/timer.c:2023
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:2036
handle_softirqs+0x2a1/0x930 kernel/softirq.c:596
__do_softirq kernel/softirq.c:630 [inline]
invoke_softirq kernel/softirq.c:470 [inline]
__irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679
irq_exit_rcu+0x5/0x20 kernel/softirq.c:691
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:default_idle+0xb/0x10 arch/x86/kernel/process.c:742
Code: 48 89 df e8 a7 10 9d f7 e9 44 ff ff ff e8 7d 07 f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 66 90 0f 00 2d 87 5d 50 00 fb f4 0f 1f 40 00 41 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 48
RSP: 0018:ffffffff8c807d88 EFLAGS: 000002c6
RAX: bd38f12409f5a200 RBX: ffffffff8a3651a7 RCX: bd38f12409f5a200
RDX: 0000000000000001 RSI: ffffffff8a8c1220 RDI: ffffffff8adf0c20
RBP: ffffffff8c807ec0 R08: ffff8880b8e3580b R09: 1ffff110171c6b01
R10: dffffc0000000000 R11: ffffed10171c6b02 R12: 1ffffffff1900fbc
R13: dffffc0000000000 R14: ffffffff8c8bc740 R15: 0000000000000000
default_idle_call+0x84/0xc0 kernel/sched/idle.c:109
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x20d/0x5a0 kernel/sched/idle.c:303
cpu_startup_entry+0x3f/0x60 kernel/sched/idle.c:401
rest_init+0x2dc/0x300 init/main.c:745
arch_call_rest_init+0xa/0xa init/main.c:905
start_kernel+0x493/0x53c init/main.c:1152
secondary_startup_64_no_verify+0xcf/0xdb
CPU: 1 PID: 18972 Comm: syz.3.4368 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__might_fault+0x74/0x120 mm/memory.c:5849
Code: 32 d5 c1 ff 45 85 ff 74 10 e8 c8 d1 c1 ff 5b 41 5c 41 5d 41 5e 41 5f 5d c3 4c 89 f7 89 ee e8 63 ed 99 ff 48 81 c3 28 05 00 00 <49> 89 dd 49 c1 ed 03 43 80 7c 25 00 00 74 08 48 89 df e8 85 bc 12
RSP: 0018:ffffc90004f0fc98 EFLAGS: 00000286
RAX: 0e9ea12d44335400 RBX: ffff88802f528528 RCX: 0e9ea12d44335400
RDX: ffff88802f528000 RSI: ffffffff8a8c23a0 RDI: ffffffff8adf0c20
RBP: 000000000000000e R08: ffffc90004f0fe5f R09: ffffc90004f0fd60
R10: dffffc0000000000 R11: fffff520009e1fcc R12: dffffc0000000000
R13: dffffc0000000000 R14: ffffffff8adeca00 R15: 0000000000000000
FS: 00007fcd2e67c6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 00000000259bb000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
_copy_from_user+0x27/0x170 lib/usercopy.c:14
copy_from_user include/linux/uaccess.h:161 [inline]
restore_sigcontext arch/x86/kernel/signal.c:92 [inline]
__ia32_sys_rt_sigreturn+0x21d/0x760 arch/x86/kernel/signal.c:675
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fcd2d73c2d9
Code: 11 06 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 c7 c0 0f 00 00 00 0f 05 <0f> 1f 80 00 00 00 00 48 81 ec 48 01 00 00 49 89 d0 64 48 8b 0c 25
RSP: 002b:00007fcd2e67ba80 EFLAGS: 00000202 ORIG_RAX: 000000000000000f
RAX: ffffffffffffffda RBX: 00007fcd2da15fa0 RCX: 00007fcd2d73c2d9
RDX: 00007fcd2e67ba80 RSI: 00007fcd2e67bbb0 RDI: 0000000000000021
RBP: 00007fcd2d808c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007fcd2da16038 R14: 00007fcd2da15fa0 R15: 00007ffe6d5ca048