rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (1 GPs behind) idle=c9bc/1/0x4000000000000000 softirq=25241/25242 fqs=27
rcu: 	(t=10500 jiffies g=16377 q=42 ncpus=2)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10445 jiffies! g16377 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=7526
rcu: rcu_preempt kthread starved for 10447 jiffies! g16377 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:27128 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 __schedule+0x1737/0x4d30
 schedule+0x165/0x360
 schedule_timeout+0x12b/0x270
 rcu_gp_fqs_loop+0x301/0x1540
 rcu_gp_kthread+0x99/0x390
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
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: 5749 Comm: sshd Not tainted 6.16.0-syzkaller-06600-g1dbf1d590d10-dirty #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:native_queued_spin_lock_slowpath+0xaf/0x8e0
Code: 00 00 00 c7 44 24 60 00 00 00 00 0f 1f 44 00 00 4c 8d 74 24 60 49 89 df 49 c1 ef 03 41 bd 01 00 00 00 eb 06 89 44 24 60 f3 90 <48> 89 df be 04 00 00 00 e8 54 66 b0 f6 48 b8 00 00 00 00 00 fc ff
RSP: 0018:ffffc900001e03a0 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffff8881103da8c0 RCX: ffffffff8b726fbc
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8881103da8c0
RBP: ffffc900001e0498 R08: ffff8881103da8c3 R09: 1ffff1102207b518
R10: dffffc0000000000 R11: ffffed102207b519 R12: 1ffff9200003c07c
R13: 0000000000000001 R14: ffffc900001e0400 R15: 1ffff1102207b518
FS:  00007f24f91b7800(0000) GS:ffff8881a3c80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbed19fefc8 CR3: 000000002759a000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 queued_spin_lock_slowpath+0x43/0x50
 do_raw_spin_lock+0x21f/0x290
 tcp_v4_rcv+0x260e/0x2f40
 ip_protocol_deliver_rcu+0x221/0x440
 ip_local_deliver_finish+0x3bb/0x6f0
 NF_HOOK+0x30c/0x3a0
 NF_HOOK+0x30c/0x3a0
 __netif_receive_skb+0x143/0x380
 process_backlog+0x60e/0x14f0
 __napi_poll+0xc7/0x360
 net_rx_action+0x707/0xe30
 handle_softirqs+0x286/0x870
 do_softirq+0xec/0x180
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x17d/0x1c0
 __dev_queue_xmit+0x1d79/0x3b50
 ip_finish_output2+0xd03/0x1160
 ip_output+0x2a1/0x3c0
 __ip_queue_xmit+0x1106/0x1b00
 __tcp_transmit_skb+0x2215/0x3680
 tcp_write_xmit+0x1862/0x67f0
 __tcp_push_pending_frames+0x97/0x360
 tcp_sendmsg_locked+0x4afd/0x5620
 tcp_sendmsg+0x2f/0x50
 __sock_sendmsg+0x19c/0x270
 sock_write_iter+0x258/0x330
 vfs_write+0x54b/0xa90
 ksys_write+0x145/0x250
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f24f8d16bf2
Code: 89 c7 48 89 44 24 08 e8 7b 34 fa ff 48 8b 44 24 08 48 83 c4 28 c3 c3 64 8b 04 25 18 00 00 00 85 c0 75 20 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 6f 48 8b 15 07 a2 0d 00 f7 d8 64 89 02 48 83
RSP: 002b:00007ffdf8d015f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000557d7f6d25e0 RCX: 00007f24f8d16bf2
RDX: 0000000000000070 RSI: 0000557d7f73acc0 RDI: 0000000000000007
RBP: 0000557d7f73acc0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000070
R13: 0000557d7f6d1460 R14: 0000557d7f6cc220 R15: 0000557d7f6d2ff0
 </TASK>
CPU: 0 UID: 0 PID: 8915 Comm: syz.3.1374 Not tainted 6.16.0-syzkaller-06600-g1dbf1d590d10-dirty #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:rcu_read_unlock_special+0x87/0x4c0
Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 b2 e8 f2 10 41 f7 c6 00 00 f0 00 74 49 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc90000007420 EFLAGS: 00000206
RAX: 7c88d4b055a33a00 RBX: 1ffff92000000e8c RCX: 7c88d4b055a33a00
RDX: 0000000000000002 RSI: ffffffff8d9792eb RDI: ffffffff8be30a00
RBP: ffffc90000007518 R08: ffffffff8fa07bf7 R09: 1ffffffff1f40f7e
R10: dffffc0000000000 R11: fffffbfff1f40f7f R12: ffffffff8e141800
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
FS:  00007fbed1a206c0(0000) GS:ffff8880b8680000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c32053d CR3: 00000000308c0000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 __rcu_read_unlock+0x84/0xe0
 unwind_next_frame+0x19ae/0x2390
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_node_noprof+0x1bb/0x3c0
 kmalloc_reserve+0xbd/0x290
 __alloc_skb+0x142/0x2d0
 __tcp_send_ack+0xaf/0x620
 tcp_delack_timer_handler+0x366/0x530
 tcp_delack_timer+0x205/0x3b0
 call_timer_fn+0x17e/0x5f0
 __run_timer_base+0x61a/0x860
 run_timer_softirq+0xb7/0x180
 handle_softirqs+0x286/0x870
 __irq_exit_rcu+0xca/0x1f0
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:__x64_sys_openat+0x0/0x170
Code: 41 5e 41 5f c3 cc cc cc cc cc e8 eb 3d 3d 09 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 41 57 41 56 41 55 41 54 53 48 83 ec 20 49 89 ff 65 48
RSP: 0018:ffffc90007b57ee8 EFLAGS: 00000246
RAX: 7c88d4b055a33a00 RBX: ffffc90007b57ef0 RCX: 7c88d4b055a33a00
RDX: 0000000000000000 RSI: 0000000000000101 RDI: ffffc90007b57f58
RBP: ffffc90007b57f48 R08: ffffffff8fa07bf7 R09: 1ffffffff1f40f7e
R10: dffffc0000000000 R11: fffffbfff1f40f7f R12: 0000000000000101
R13: 0000000000000101 R14: ffffc90007b57f58 R15: ffff888123b69cc0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbed0b8eb69
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:00007fbed1a20038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fbed0db6080 RCX: 00007fbed0b8eb69
RDX: 0000000000000000 RSI: 0000200000000080 RDI: ffffffffffffff9c
RBP: 00007fbed0c11df1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fbed0db6080 R15: 00007ffcfb0ab3f8
 </TASK>
sched: DL replenish lagged too much
