------------[ cut here ]------------
WARNING: net/mptcp/subflow.c:1527 at subflow_data_ready+0x40b/0x790 net/mptcp/subflow.c:1527, CPU#0: ksoftirqd/0/15
Modules linked in:
CPU: 0 UID: 0 PID: 15 Comm: ksoftirqd/0 Tainted: G     U    I  L      syzkaller #0 PREEMPT(full) 
Tainted: [U]=USER, [I]=FIRMWARE_WORKAROUND, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:subflow_data_ready+0x40b/0x790 net/mptcp/subflow.c:1527
Code: 89 ee e8 38 4e 5d f6 40 84 ed 75 21 e8 ee 53 5d f6 44 89 fe bf 07 00 00 00 e8 81 4e 5d f6 41 83 ff 07 74 09 e8 d6 53 5d f6 90 <0f> 0b 90 e8 cd 53 5d f6 48 89 df e8 f5 ac ff ff 31 ff 89 c5 89 c6
RSP: 0018:ffffc90000007548 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff88809cef72c0 RCX: ffffffff8b6104df
RDX: ffff88801da8bd00 RSI: ffffffff8b6104ea RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000007
R10: 0000000000000004 R11: ffff88801da8c830 R12: ffff888034ac1800
R13: 1ffff92000000ea9 R14: ffff88802ab18800 R15: 0000000000000004
FS:  0000000000000000(0000) GS:ffff8881248fc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000098030 CR3: 0000000093fac000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 tcp_data_ready+0x114/0x5a0 net/ipv4/tcp_input.c:5371
 tcp_data_queue+0x1ac2/0x4ff0 net/ipv4/tcp_input.c:5461
 tcp_rcv_state_process+0xfb6/0x6540 net/ipv4/tcp_input.c:7185
 tcp_v4_do_rcv+0x68e/0x10a0 net/ipv4/tcp_ipv4.c:1904
 tcp_v4_rcv+0x3077/0x4db0 net/ipv4/tcp_ipv4.c:2324
 ip_protocol_deliver_rcu+0xba/0x4c0 net/ipv4/ip_input.c:207
 ip_local_deliver_finish+0x3f2/0x720 net/ipv4/ip_input.c:241
 NF_HOOK include/linux/netfilter.h:318 [inline]
 NF_HOOK include/linux/netfilter.h:312 [inline]
 ip_local_deliver+0x18e/0x1f0 net/ipv4/ip_input.c:262
 dst_input include/net/dst.h:474 [inline]
 ip_rcv_finish net/ipv4/ip_input.c:453 [inline]
 NF_HOOK include/linux/netfilter.h:318 [inline]
 NF_HOOK include/linux/netfilter.h:312 [inline]
 ip_rcv+0x2e0/0x600 net/ipv4/ip_input.c:573
 __netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:6137
 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6250
 process_backlog+0x4a2/0x1650 net/core/dev.c:6602
 __napi_poll.constprop.0+0xb3/0x540 net/core/dev.c:7666
 napi_poll net/core/dev.c:7729 [inline]
 net_rx_action+0x9f9/0xfa0 net/core/dev.c:7881
 handle_softirqs+0x219/0x950 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:finish_task_switch.isra.0+0x210/0xbd0 kernel/sched/core.c:5114
Code: ac 08 00 00 44 8b 05 03 70 fe 0e 45 85 c0 0f 85 be 01 00 00 4c 89 e7 e8 ae f6 ff ff e8 a9 d2 3b 00 fb 65 48 8b 1d a8 98 27 12 <48> 8d bb 48 16 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1
RSP: 0018:ffffc90000147bc8 EFLAGS: 00000206
RAX: 0000000001411edb RBX: ffff88801da8bd00 RCX: ffffffff81c6791f
RDX: 0000000000000000 RSI: ffffffff8daca42c RDI: ffffffff8bf2b500
RBP: ffffc90000147c10 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff9088e6d7 R11: ffff88801da8c830 R12: ffff8880b843adc0
R13: ffff88803509bd00 R14: ffff8880781f3d00 R15: ffff8880b843bbf0
 context_switch kernel/sched/core.c:5259 [inline]
 __schedule+0x1141/0x6150 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6960
 smpboot_thread_fn+0x8e6/0xae0 kernel/smpboot.c:156
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
----------------
Code disassembly (best guess), 2 bytes skipped:
   0:	00 00                	add    %al,(%rax)
   2:	44 8b 05 03 70 fe 0e 	mov    0xefe7003(%rip),%r8d        # 0xefe700c
   9:	45 85 c0             	test   %r8d,%r8d
   c:	0f 85 be 01 00 00    	jne    0x1d0
  12:	4c 89 e7             	mov    %r12,%rdi
  15:	e8 ae f6 ff ff       	call   0xfffff6c8
  1a:	e8 a9 d2 3b 00       	call   0x3bd2c8
  1f:	fb                   	sti
  20:	65 48 8b 1d a8 98 27 	mov    %gs:0x122798a8(%rip),%rbx        # 0x122798d0
  27:	12
* 28:	48 8d bb 48 16 00 00 	lea    0x1648(%rbx),%rdi <-- trapping instruction
  2f:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  36:	fc ff df
  39:	48 89 fa             	mov    %rdi,%rdx
  3c:	48                   	rex.W
  3d:	c1                   	.byte 0xc1