rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (10499 ticks this GP) idle=0d8c/1/0x4000000000000000 softirq=22402/22402 fqs=4169
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:   970295          0            0
rcu: 	cputime:    25758      26720          116   ==> 52490(ms)
rcu: 	(t=10501 jiffies g=14725 q=11250 ncpus=2)
CPU: 1 UID: 0 PID: 7694 Comm: syz.1.544 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 d2 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:ffffc900001e0440 EFLAGS: 00000206
RAX: 2931d4bc86fc6b00 RBX: 1ffff9200003c090 RCX: 2931d4bc86fc6b00
RDX: 0000000000000002 RSI: ffffffff8d998874 RDI: ffffffff8be29f40
RBP: ffffc900001e0538 R08: ffffffff8fa1e8f7 R09: 1ffffffff1f43d1e
R10: dffffc0000000000 R11: fffffbfff1f43d1f R12: ffffffff8e144400
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000002
FS:  00007f661c5f66c0(0000) GS:ffff8881a3c1f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557fe427d0 CR3: 0000000109926000 CR4: 00000000000006f0
DR0: 0000200000000300 DR1: 0000200000000300 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
 lapb_send_control+0x38/0x3e0
 lapb_t1timer_expiry+0x699/0xab0
 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:_raw_spin_unlock_irqrestore+0xa8/0x110
Code: 74 05 e8 5b 9e 56 f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> a3 cc 1f f6 65 8b 05 bc f9 2e 07 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc9000a2475e0 EFLAGS: 00000206
RAX: 2931d4bc86fc6b00 RBX: 0000000000000a02 RCX: 2931d4bc86fc6b00
RDX: 0000000000000007 RSI: ffffffff8d998874 RDI: 0000000000000001
RBP: ffffc9000a247660 R08: ffffffff8fa1e8f7 R09: 1ffffffff1f43d1e
R10: dffffc0000000000 R11: fffffbfff1f43d1f R12: dffffc0000000000
R13: 0000000000040001 R14: ffff88801a4409c0 R15: 1ffff92001448ebc
 __slab_free+0x2d7/0x400
 qlist_free_all+0x97/0x140
 kasan_quarantine_reduce+0x148/0x160
 __kasan_slab_alloc+0x22/0x80
 kmem_cache_alloc_noprof+0x1c1/0x3c0
 vm_area_dup+0x2b/0x680
 dup_mmap+0x90c/0x1ac0
 copy_mm+0x13c/0x4b0
 copy_process+0x16d3/0x3b80
 kernel_clone+0x21e/0x870
 __x64_sys_clone+0x18b/0x1e0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f661e78e9a9
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:00007f661c5f5fe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f661e9b5fa0 RCX: 00007f661e78e9a9
RDX: 0000000000000000 RSI: 0000200000001800 RDI: 00000000008ca000
RBP: 00007f661e810d69 R08: 0000200000001900 R09: 0000200000001900
R10: 00002000000018c0 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f661e9b5fa0 R15: 00007fff35b77ae8
 </TASK>
sched: DL replenish lagged too much
