------------[ cut here ]------------
WARNING: CPU: 0 PID: 7430 at kernel/rcu/tree_stall.h:1001 rcu_check_gp_start_stall+0x2dc/0x460 kernel/rcu/tree_stall.h:993
Modules linked in:
CPU: 0 PID: 7430 Comm: syz.0.278 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:rcu_check_gp_start_stall+0x2dc/0x460 kernel/rcu/tree_stall.h:1001
Code: ff ff ff 48 c7 c7 a0 d4 ed 96 be 04 00 00 00 e8 4a d0 6c 00 48 89 df b8 01 00 00 00 87 05 4c a4 7d 15 85 c0 0f 85 19 ff ff ff <0f> 0b 48 81 ff 80 51 d3 8c 74 47 48 c7 c0 ec 55 4a 8e 48 c1 e8 03
RSP: 0018:ffffc90000007bb8 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffffffff8cd35180 RCX: ffffffff81703046
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff8cd35180
RBP: ffffc90000007e30 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff2ddba94 R12: 0000000000002904
R13: 1ffff110171c79e2 R14: 0000000000000a02 R15: dffffc0000000000
FS:  00007ff1ac47a6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff1ac49af98 CR3: 000000007687e000 CR4: 00000000003506f0
Call Trace:
 <IRQ>
 rcu_core+0x612/0x1720 kernel/rcu/tree.c:2462
 handle_softirqs+0x280/0x820 kernel/softirq.c:578
 __do_softirq kernel/softirq.c:612 [inline]
 invoke_softirq kernel/softirq.c:452 [inline]
 __irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661
 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:arch_atomic_try_cmpxchg arch/x86/include/asm/atomic.h:115 [inline]
RIP: 0010:raw_atomic_try_cmpxchg_acquire include/linux/atomic/atomic-arch-fallback.h:2151 [inline]
RIP: 0010:atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1296 [inline]
RIP: 0010:queued_spin_lock include/asm-generic/qspinlock.h:111 [inline]
RIP: 0010:do_raw_spin_lock+0x12e/0x2c0 kernel/locking/spinlock_debug.c:115
Code: 00 48 89 df be 04 00 00 00 e8 ce b6 74 00 48 8d 7c 24 40 be 04 00 00 00 e8 bf b6 74 00 8b 44 24 40 b9 01 00 00 00 f0 0f b1 0b <0f> 85 d9 00 00 00 65 8b 1d e1 6b 9b 7e 48 b9 00 00 00 00 00 fc ff
RSP: 0018:ffffc9000cbbf9e0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff88805e48b0d0 RCX: 0000000000000001
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc9000cbbfa20
RBP: ffffc9000cbbfa90 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52001977f44 R12: ffff88805e48b0e0
R13: ffff88805e48b0d8 R14: 1ffff1100bc9161c R15: 1ffff1100bc9161b
 __mutex_lock_common kernel/locking/mutex.c:617 [inline]
 __mutex_lock+0x3b4/0xcc0 kernel/locking/mutex.c:747
 tty_write_lock+0x5a/0x90 drivers/tty/tty_io.c:953
 set_termios+0x46e/0x6b0 drivers/tty/tty_ioctl.c:500
 tty_mode_ioctl+0x481/0x740 drivers/tty/tty_ioctl.c:-1
 tty_ioctl+0x9bd/0xdd0 drivers/tty/tty_io.c:2788
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ff1ab58f749
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:00007ff1ac47a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ff1ab7e6180 RCX: 00007ff1ab58f749
RDX: 0000200000000000 RSI: 00000000402c542c RDI: 0000000000000007
RBP: 00007ff1ab613f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff1ab7e6218 R14: 00007ff1ab7e6180 R15: 00007ffe025650f8
 </TASK>
----------------
Code disassembly (best guess):
   0:	00 48 89             	add    %cl,-0x77(%rax)
   3:	df be 04 00 00 00    	fistpll 0x4(%rsi)
   9:	e8 ce b6 74 00       	call   0x74b6dc
   e:	48 8d 7c 24 40       	lea    0x40(%rsp),%rdi
  13:	be 04 00 00 00       	mov    $0x4,%esi
  18:	e8 bf b6 74 00       	call   0x74b6dc
  1d:	8b 44 24 40          	mov    0x40(%rsp),%eax
  21:	b9 01 00 00 00       	mov    $0x1,%ecx
  26:	f0 0f b1 0b          	lock cmpxchg %ecx,(%rbx)
* 2a:	0f 85 d9 00 00 00    	jne    0x109 <-- trapping instruction
  30:	65 8b 1d e1 6b 9b 7e 	mov    %gs:0x7e9b6be1(%rip),%ebx        # 0x7e9b6c18
  37:	48                   	rex.W
  38:	b9 00 00 00 00       	mov    $0x0,%ecx
  3d:	00 fc                	add    %bh,%ah
  3f:	ff                   	.byte 0xff