rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (10499 ticks this GP) idle=5c44/1/0x4000000000000000 softirq=13566/13566 fqs=4961
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:  1112624          0            0
rcu: 	cputime:    25470      26908           82   ==> 52380(ms)
rcu: 	(t=10500 jiffies g=7941 q=2924 ncpus=2)
CPU: 1 UID: 0 PID: 5997 Comm: syz.0.31 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:ffffc900001dffc0 EFLAGS: 00000206
RAX: 9126816587110b00 RBX: 1ffff9200003c000 RCX: 9126816587110b00
RDX: 0000000000000002 RSI: ffffffff8d99883e RDI: ffffffff8be29f40
RBP: ffffc900001e00b8 R08: ffffffff8fa1e8f7 R09: 1ffffffff1f43d1e
R10: dffffc0000000000 R11: fffffbfff1f43d1f R12: ffffffff8e144400
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000002
FS:  00007fb5975406c0(0000) GS:ffff8881a3c1f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb59753ffc8 CR3: 00000001156a6000 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_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:ffffc900044b76e0 EFLAGS: 00000282
RAX: 9126816587110b00 RBX: 0000000000000000 RCX: 9126816587110b00
RDX: 0000000000000007 RSI: ffffffff8d99883e RDI: 0000000000000001
RBP: ffffc900044b7780 R08: ffffffff8fa1e8f7 R09: 1ffffffff1f43d1e
R10: dffffc0000000000 R11: fffffbfff1f43d1f R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff92000896edc
 irqentry_exit+0x6f/0x90
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:mtree_range_walk+0x1ab/0x840
Code: f6 0f 85 80 04 00 00 e8 83 d0 59 f6 4d 8d b7 f8 00 00 00 4c 89 f0 48 c1 e8 03 0f b6 04 28 84 c0 0f 85 b9 04 00 00 41 0f b6 06 <89> 44 24 04 48 8b 5c 24 10 4d 89 e6 4c 8b 64 24 28 eb 33 e8 4d d0
RSP: 0018:ffffc900044b7848 EFLAGS: 00000246
RAX: 0000000000000009 RBX: 000000000000000f RCX: ffff888021403980
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: dffffc0000000000 R08: ffff888021403980 R09: 0000000000000003
R10: 0000000000000003 R11: 0000000000000000 R12: ffff88810bf41808
R13: 0000000000000001 R14: ffff88810bf418f8 R15: ffff88810bf41800
 mas_find+0x798/0xc10
 acct_collect+0x18c/0x770
 do_exit+0x5c3/0x22e0
 do_group_exit+0x21c/0x2d0
 get_signal+0x1286/0x1340
 arch_do_signal_or_restart+0x9a/0x750
 exit_to_user_mode_loop+0x75/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb59678e9a9
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:00007fb597540038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: 0000000000000046 RBX: 00007fb5969b6160 RCX: 00007fb59678e9a9
RDX: bfffffffffffffff RSI: 0000000000000000 RDI: 0000200000000180
RBP: 00007fb596810d69 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007fb5969b6160 R15: 00007ffe187f1c68
 </TASK>
sched: DL replenish lagged too much
