rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6919/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=14101, q=1083 ncpus=2)
task:syz.0.205 state:R running task stack:27928 pid:6919 tgid:6917 ppid:5853 task_flags:0x400040 flags:0x00004004
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:on_stack arch/x86/include/asm/stacktrace.h:55 [inline]
RIP: 0010:unwind_next_frame+0x1625/0x20a0 arch/x86/kernel/unwind_orc.c:665
Code: 00 e9 c1 f9 ff ff 48 b8 00 00 00 00 00 fc ff df 48 8b 14 24 48 c1 ea 03 80 3c 02 00 0f 85 56 05 00 00 49 8d 7d 08 49 8b 5d 38 <48> b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f
RSP: 0018:ffffc900046ef1d8 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: ffffc900046efb00 RCX: ffffc900046f0000
RDX: 1ffff920008dde50 RSI: ffffc900046efad0 RDI: ffffc900046ef250
RBP: ffffc900046efce8 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000086369 R12: ffffc900046ef298
R13: ffffc900046ef248 R14: ffffc900046efb00 R15: ffffc900046ef27c
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
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
unpoison_slab_object mm/kasan/common.c:330 [inline]
__kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:356
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4191 [inline]
slab_alloc_node mm/slub.c:4240 [inline]
kmem_cache_alloc_node_noprof+0x1d5/0x3b0 mm/slub.c:4292
__alloc_skb+0x2b2/0x380 net/core/skbuff.c:659
alloc_skb include/linux/skbuff.h:1336 [inline]
alloc_skb_with_frags+0xe0/0x860 net/core/skbuff.c:6665
sock_alloc_send_pskb+0x7fb/0x990 net/core/sock.c:2958
unix_dgram_sendmsg+0x3e9/0x17f0 net/unix/af_unix.c:2153
sock_sendmsg_nosec net/socket.c:714 [inline]
__sock_sendmsg net/socket.c:729 [inline]
____sys_sendmsg+0xa98/0xc70 net/socket.c:2614
___sys_sendmsg+0x134/0x1d0 net/socket.c:2668
__sys_sendmmsg+0x200/0x420 net/socket.c:2757
__do_sys_sendmmsg net/socket.c:2784 [inline]
__se_sys_sendmmsg net/socket.c:2781 [inline]
__x64_sys_sendmmsg+0x9c/0x100 net/socket.c:2781
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: 0033:0x7f559878ebe9
RSP: 002b:00007f559964b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f55989c6090 RCX: 00007f559878ebe9
RDX: 0000000000000318 RSI: 00002000000bd000 RDI: 0000000000000007
RBP: 00007f5598811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f55989c6128 R14: 00007f55989c6090 R15: 00007ffd5c11d8b8
rcu: rcu_preempt kthread timer wakeup didn't happen for 10539 jiffies! g14101 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=6094
rcu: rcu_preempt kthread starved for 10545 jiffies! g14101 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:27928 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: 1299 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:kasan_check_range+0x16c/0x1b0 mm/kasan/generic.c:190
Code: 46 ff ff ff 48 85 d2 74 18 48 01 ea eb 09 48 83 c0 01 48 39 d0 74 0a 80 38 00 74 f2 e9 75 ff ff ff 5b b8 01 00 00 00 5d 41 5c 4f 59 75 09 b8 01 00 00 00 e9 45 59 75 09 48 29 c3 48 89 da 49
RSP: 0018:ffffc90004d3f940 EFLAGS: 00000046
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: 000020000004d030 CR3: 0000000057c10000 CR4: 00000000003526f0
Call Trace:
instrument_atomic_read include/linux/instrumented.h:68 [inline]
_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
cpumask_test_cpu include/linux/cpumask.h:646 [inline]
cpu_online include/linux/cpumask.h:1205 [inline]
trace_irq_enable.constprop.0+0x2f/0x120 include/trace/events/preemptirq.h:40
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