rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6625/2:b..l
rcu: (detected by 1, t=10502 jiffies, g=11465, q=686 ncpus=2)
task:syz.0.130 state:R running task stack:25160 pid:6625 tgid:6625 ppid:5810 task_flags:0x400040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7256
irqentry_exit+0x36/0x90 kernel/entry/common.c:211
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5872
Code: 57 0b 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 a2 14 ea 0e 0f 82 74 02 00 00 8b 35 1a 45 ea 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 b9 56 0b 12 0f 85 c7 02 00 00 48 83 c4
RSP: 0018:ffffc9001a86f970 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8e3c4460 RCX: 00000000c639c71c
RDX: 0000000000000000 RSI: ffffffff8dadd953 RDI: ffffffff8bf1e2c0
RBP: 0000000000000002 R08: f501fefe41178ce3 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
percpu_ref_tryget_many include/linux/percpu-refcount.h:241 [inline]
percpu_ref_tryget include/linux/percpu-refcount.h:266 [inline]
css_tryget include/linux/cgroup_refcnt.h:45 [inline]
css_tryget include/linux/cgroup_refcnt.h:42 [inline]
get_mem_cgroup_from_objcg+0xf5/0x210 include/linux/memcontrol.h:519
obj_cgroup_charge_pages mm/memcontrol.c:2797 [inline]
__memcg_kmem_charge_page+0xc9/0x420 mm/memcontrol.c:2843
memcg_kmem_charge_page include/linux/memcontrol.h:1756 [inline]
memcg_charge_kernel_stack kernel/fork.c:270 [inline]
memcg_charge_kernel_stack+0xc3/0x1f0 kernel/fork.c:261
alloc_thread_stack_node kernel/fork.c:293 [inline]
dup_task_struct kernel/fork.c:881 [inline]
copy_process+0x548/0x76a0 kernel/fork.c:2012
kernel_clone+0xfc/0x930 kernel/fork.c:2609
__do_sys_clone3+0x212/0x290 kernel/fork.c:2911
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fae14bc3609
RSP: 002b:00007ffdd834f518 EFLAGS: 00000206 ORIG_RAX: 00000000000001b3
RAX: ffffffffffffffda RBX: 00007fae14b459f0 RCX: 00007fae14bc3609
RDX: 00007fae14b459f0 RSI: 0000000000000058 RDI: 00007ffdd834f560
RBP: 00007fae159946c0 R08: 00007fae159946c0 R09: 00007ffdd834f647
R10: 0000000000000008 R11: 0000000000000206 R12: ffffffffffffffa8
R13: 000000000000006e R14: 00007ffdd834f560 R15: 00007ffdd834f648
rcu: rcu_preempt kthread timer wakeup didn't happen for 10513 jiffies! g11465 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=0 timer-softirq=7823
rcu: rcu_preempt kthread starved for 10514 jiffies! g11465 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:28776 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7026
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 1297 Comm: aoe_tx0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:write_comp_data+0x8b/0x90 kernel/kcov.c:272
Code: 00 00 4a 8d 34 dd 28 00 00 00 48 39 f2 72 1b 48 83 c7 01 48 89 38 4c 89 44 30 e0 4c 89 4c 30 e8 4c 89 54 30 f0 4a 89 4c d8 20 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3
RSP: 0018:ffffc9000447f978 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff888141fc8be8 RCX: ffffffff852eac58
RDX: ffff888028d92480 RSI: 0000000000000000 RDI: 0000000000000001
RBP: ffff888141fc8f84 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000001
R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff8881249d9000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2fc0cff8 CR3: 0000000022303000 CR4: 00000000003526f0
Call Trace:
arch_atomic_try_cmpxchg arch/x86/include/asm/atomic.h:107 [inline]
raw_atomic_try_cmpxchg include/linux/atomic/atomic-arch-fallback.h:2130 [inline]
raw_atomic_fetch_add_unless include/linux/atomic/atomic-arch-fallback.h:2431 [inline]
raw_atomic_add_unless include/linux/atomic/atomic-arch-fallback.h:2456 [inline]
atomic_add_unless include/linux/atomic/atomic-instrumented.h:1518 [inline]
uart_port_ref drivers/tty/serial/serial_core.c:67 [inline]
uart_port_ref_lock drivers/tty/serial/serial_core.c:80 [inline]
uart_write+0xd8/0xb30 drivers/tty/serial/serial_core.c:624
handle_tx+0x204/0x630 drivers/net/caif/caif_serial.c:222
__netdev_start_xmit include/linux/netdevice.h:5248 [inline]
netdev_start_xmit include/linux/netdevice.h:5257 [inline]
xmit_one net/core/dev.c:3845 [inline]
dev_hard_start_xmit+0x97/0x740 net/core/dev.c:3861
__dev_queue_xmit+0xa46/0x4490 net/core/dev.c:4763
dev_queue_xmit include/linux/netdevice.h:3365 [inline]
tx+0xcc/0x190 drivers/block/aoe/aoenet.c:62
kthread+0x1e4/0x3e0 drivers/block/aoe/aoecmd.c:1241
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245