rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6529/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=41773, q=112 ncpus=2)
task:syz-executor state:R running task stack:23496 pid:6529 tgid:6529 ppid:6519 task_flags:0x400140 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7288
irqentry_exit+0x36/0x90 kernel/entry/common.c:197
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5872
Code: e6 3e 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 22 a2 13 0f 0f 82 74 02 00 00 8b 35 da d3 13 0f 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 79 e6 3e 12 0f 85 c7 02 00 00 48 83 c4
RSP: 0018:ffffc900047df540 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8e5c1260 RCX: 000000004f21babc
RDX: 0000000000000000 RSI: ffffffff8de2cdb8 RDI: ffffffff8c162d80
RBP: 0000000000000002 R08: 7d3ab187bdb960b1 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
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]
is_module_text_address+0x33/0x220 kernel/module/main.c:3845
kernel_text_address kernel/extable.c:119 [inline]
kernel_text_address+0x81/0x100 kernel/extable.c:94
__kernel_text_address+0xd/0x40 kernel/extable.c:79
unwind_get_return_address+0x59/0xa0 arch/x86/kernel/unwind_orc.c:369
arch_stack_walk+0xa6/0x100 arch/x86/kernel/stacktrace.c:26
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576
poison_slab_object mm/kasan/common.c:243 [inline]
__kasan_slab_free+0x60/0x70 mm/kasan/common.c:275
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2422 [inline]
slab_free mm/slub.c:4695 [inline]
kfree+0x2b4/0x4d0 mm/slub.c:4894
tomoyo_realpath_from_path+0x19f/0x6e0 security/tomoyo/realpath.c:286
tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
tomoyo_path_perm+0x274/0x460 security/tomoyo/file.c:822
security_inode_getattr+0x116/0x290 security/security.c:2377
vfs_getattr fs/stat.c:259 [inline]
vfs_statx_path fs/stat.c:299 [inline]
vfs_statx+0x121/0x3f0 fs/stat.c:356
vfs_fstatat+0x7b/0xf0 fs/stat.c:375
__do_sys_newfstatat+0x97/0x120 fs/stat.c:542
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff0b338d3fa
RSP: 002b:00007ffc5cae94c8 EFLAGS: 00000286 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff0b338d3fa
RDX: 00007ffc5cae94f0 RSI: 00007ffc5cae9580 RDI: 00000000ffffff9c
RBP: 00007ffc5cae9580 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000286 R12: 00007ffc5caea610
R13: 00007ff0b3411c05 R14: 000000000005c4b4 R15: 00007ffc5caea650
rcu: rcu_preempt kthread timer wakeup didn't happen for 10543 jiffies! g41773 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=28865
rcu: rcu_preempt kthread starved for 10544 jiffies! g41773 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:27784 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7058
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2285
kthread+0x3c2/0x780 kernel/kthread.c:463
ret_from_fork+0x5d4/0x6f0 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: 1298 Comm: aoe_tx0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:trace_irq_enable.constprop.0+0x37/0x120 include/trace/events/preemptirq.h:40
Code: 07 0f 87 f3 00 00 00 89 db be 08 00 00 00 48 89 d8 48 c1 e8 06 48 8d 3c c5 90 6b ab 90 e8 81 81 5e 00 48 0f a3 1d 19 f7 e7 0e <0f> 82 92 00 00 00 5b 5d c3 cc cc cc cc 48 89 fb 65 8b 05 a6 3b 13
RSP: 0018:ffffc90004a4f948 EFLAGS: 00000047
RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff81c3746f
RDX: fffffbfff2156d73 RSI: 0000000000000008 RDI: ffffffff90ab6b90
RBP: 0000000000000293 R08: 0000000000000000 R09: fffffbfff2156d72
R10: ffffffff90ab6b97 R11: 0000000000000000 R12: ffffffff8f2ed540
R13: ffffffff9b115ca8 R14: 0000000000000000 R15: ffffffff9b115ce0
FS: 0000000000000000(0000) GS:ffff8881247b5000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000010000 CR3: 00000000753ab000 CR4: 00000000003526f0
Call Trace:
trace_hardirqs_on+0x26/0x40 kernel/trace/trace_preemptirq.c:73
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
_raw_spin_unlock_irqrestore+0x52/0x80 kernel/locking/spinlock.c:194
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
uart_port_unlock_irqrestore include/linux/serial_core.h:788 [inline]
uart_port_unlock_deref drivers/tty/serial/serial_core.c:91 [inline]
uart_port_unlock_deref drivers/tty/serial/serial_core.c:88 [inline]
uart_write_room+0x2d9/0x940 drivers/tty/serial/serial_core.c:650
tty_write_room+0x66/0x90 drivers/tty/tty_ioctl.c:69
handle_tx+0x14f/0x630 drivers/net/caif/caif_serial.c:212
__netdev_start_xmit include/linux/netdevice.h:5222 [inline]
netdev_start_xmit include/linux/netdevice.h:5231 [inline]
xmit_one net/core/dev.c:3839 [inline]
dev_hard_start_xmit+0x94/0x740 net/core/dev.c:3855
__dev_queue_xmit+0xa46/0x4490 net/core/dev.c:4725
dev_queue_xmit include/linux/netdevice.h:3361 [inline]
tx+0xcc/0x190 drivers/block/aoe/aoenet.c:62
kthread+0x1e4/0x3e0 drivers/block/aoe/aoecmd.c:1241
kthread+0x3c2/0x780 kernel/kthread.c:463
ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245