rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (1 GPs behind) idle=0654/1/0x4000000000000000 softirq=15824/15825 fqs=5247
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:   964168          1            0
rcu: 	cputime:    24229      28270           99   ==> 52510(ms)
rcu: 	(t=10502 jiffies g=7965 q=2192 ncpus=2)
CPU: 1 UID: 0 PID: 6078 Comm: syz.1.71 Not tainted 6.16.0-rc6-syzkaller-00411-g95993dc3039e-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 62 2c f8 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:ffffc900001e0000 EFLAGS: 00000206
RAX: 605396840ff04700 RBX: 1ffff9200003c008 RCX: 605396840ff04700
RDX: 0000000000000002 RSI: ffffffff8d99883e RDI: ffffffff8be29f40
RBP: ffffc900001e00f8 R08: ffffffff8fa1e8f7 R09: 1ffffffff1f43d1e
R10: dffffc0000000000 R11: fffffbfff1f43d1f R12: ffffffff8e144400
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000002
FS:  00007f156b8576c0(0000) GS:ffff8881a3c1f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c274351 CR3: 0000000111b48000 CR4: 00000000000006f0
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
 __alloc_skb+0x112/0x2d0
 tcp_make_synack+0xc9/0x1c00
 tcp_v4_send_synack+0x101/0xa50
 tcp_rtx_synack+0x176/0x5c0
 reqsk_timer_handler+0x773/0xd90
 call_timer_fn+0x17e/0x5f0
 __run_timer_base+0x61a/0x860
 run_timer_softirq+0x67/0x180
 handle_softirqs+0x286/0x870
 __irq_exit_rcu+0xca/0x1f0
 irq_exit_rcu+0x9/0x30
 sysvec_irq_work+0xa3/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_irq_work+0x1a/0x20
RIP: 0010:preempt_schedule_irq+0xb0/0x150
Code: 24 20 f6 44 24 21 02 74 0c 90 0f 0b 48 f7 03 08 00 00 00 74 64 bf 01 00 00 00 e8 8b 2d 21 f6 e8 c6 00 58 f6 fb bf 01 00 00 00 <e8> 1b ab ff ff 48 c7 44 24 40 00 00 00 00 9c 8f 44 24 40 8b 44 24
RSP: 0018:ffffc9000321ee40 EFLAGS: 00000286
RAX: 605396840ff04700 RBX: 0000000000000000 RCX: 605396840ff04700
RDX: 0000000000000006 RSI: ffffffff8d99883e RDI: 0000000000000001
RBP: ffffc9000321eef0 R08: ffffffff8fa1e8f7 R09: 1ffffffff1f43d1e
R10: dffffc0000000000 R11: fffffbfff1f43d1f R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff92000643dc8
 irqentry_exit+0x6f/0x90
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:__build_skb_around+0x0/0x3e0
Code: f8 5b 41 5e 41 5f c3 cc cc cc cc cc e8 29 0d 72 f8 eb eb 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <55> 41 57 41 56 41 55 41 54 53 48 83 ec 10 41 89 d6 49 89 f4 48 89
RSP: 0018:ffffc9000321efb0 EFLAGS: 00000246
RAX: ffff88811e56bb80 RBX: 0000000000000001 RCX: 0000000000000000
RDX: 00000000000002c0 RSI: ffff88810e4e2680 RDI: ffff88811e56bb80
RBP: 00000000ffffffff R08: ffff88811e56bc47 R09: 0000000000000000
R10: ffff88811e56bb80 R11: ffffed1023cad789 R12: ffff88810e4e2680
R13: 0000000000000cc0 R14: ffff88811e56bb80 R15: 00000000000002c0
 __alloc_skb+0x179/0x2d0
 tcp_stream_alloc_skb+0x3d/0x340
 tcp_connect+0x146f/0x4ef0
 tcp_v6_connect+0x1202/0x1880
 mptcp_connect+0x530/0x790
 __inet_stream_connect+0x2ae/0xe80
 tcp_sendmsg_fastopen+0x3a7/0x5e0
 mptcp_sendmsg_fastopen+0x17d/0x580
 mptcp_sendmsg+0x176c/0x1970
 __sock_sendmsg+0xe5/0x270
 ____sys_sendmsg+0x505/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __x64_sys_sendmsg+0x19b/0x260
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f156a98e9a9
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:00007f156b857038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f156abb6080 RCX: 00007f156a98e9a9
RDX: e07e872420dfefca RSI: 0000200000000780 RDI: 0000000000000003
RBP: 00007f156aa10d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f156abb6080 R15: 00007fff8b5fcae8
 </TASK>
sched: DL replenish lagged too much
