------------[ cut here ]------------ WARNING: CPU: 0 PID: 14 at kernel/rcu/tasks.h:901 trc_read_check_handler+0x248/0x2e0 kernel/rcu/tasks.h:920 Modules linked in: CPU: 0 PID: 14 Comm: rcu_preempt Not tainted 5.14.0-rc3-next-20210730-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:trc_read_check_handler+0x248/0x2e0 kernel/rcu/tasks.h:901 Code: 48 c1 ea 03 0f b6 04 02 4c 89 e2 83 e2 07 38 d0 7f 0c 84 c0 74 08 4c 89 e7 e8 b4 6f 5a 00 c6 83 19 04 00 00 01 e9 5a fe ff ff <0f> 0b 31 c9 ba 01 00 00 00 be 03 00 00 00 48 c7 c7 e0 dd 97 8b e8 RSP: 0018:ffffc90000007f78 EFLAGS: 00010047 RAX: 0000000000000001 RBX: ffff888011ac9c80 RCX: ffffffff8160ce50 RDX: fffffbfff2045b5c RSI: 0000000000000004 RDI: ffffffff9022dae0 RBP: ffff888011ac9c80 R08: 0000000000000001 R09: 0000000000000003 R10: fffffbfff2045b5c R11: 0000000000000000 R12: 0000000000000000 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880b9d32a08 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0567faf900 CR3: 000000003526a000 CR4: 00000000001526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: flush_smp_call_function_queue+0x34b/0x640 kernel/smp.c:663 __sysvec_call_function_single+0x95/0x3d0 arch/x86/kernel/smp.c:248 sysvec_call_function_single+0x8e/0xc0 arch/x86/kernel/smp.c:243 asm_sysvec_call_function_single+0x12/0x20 arch/x86/include/asm/idtentry.h:646 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:199 Code: 0f 1f 44 00 00 55 48 8b 74 24 08 48 89 fd 48 83 c7 18 e8 6e ca 2a f8 48 89 ef e8 16 40 2b f8 e8 71 7b 4b f8 fb bf 01 00 00 00 86 18 1f f8 65 8b 05 6f 8e d1 76 85 c0 74 02 5d c3 e8 eb e3 cf RSP: 0018:ffffc90000d37de0 EFLAGS: 00000202 RAX: 0000000000147eef RBX: ffffffff8b987708 RCX: 1ffffffff1ada649 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffffffff8b987640 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff817bdce8 R11: ffffffff8b987718 R12: ffff8880b9c32800 R13: 0000000000000000 R14: ffffffff8b987640 R15: dffffc0000000000 rcu_gp_init+0x859/0x12a0 kernel/rcu/tree.c:1864 rcu_gp_kthread+0xab/0x320 kernel/rcu/tree.c:2118 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295