------------[ cut here ]------------ failed to allocate ring buffer on CPU 0 WARNING: kernel/trace/ring_buffer.c:7976 at trace_rb_cpu_prepare+0x330/0x3c0 kernel/trace/ring_buffer.c:7975, CPU#0: syz.2.5252/21074 Modules linked in: CPU: 0 UID: 0 PID: 21074 Comm: syz.2.5252 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:trace_rb_cpu_prepare+0x332/0x3c0 kernel/trace/ring_buffer.c:7975 Code: 08 f0 48 0f ab 03 31 c0 48 83 c4 30 5b 41 5c 41 5d 41 5e 41 5f 5d e9 7d 88 8a 09 cc e8 87 3b fc ff 48 8d 3d 30 11 0b 0e 89 ee <67> 48 0f b9 3a b8 f4 ff ff ff eb d2 e8 6d 3b fc ff e9 ef fe ff ff RSP: 0018:ffffc90009a4f7c0 EFLAGS: 00010287 RAX: ffffffff81c96829 RBX: dffffc0000000000 RCX: 0000000000080000 RDX: ffffc900135ae000 RSI: 0000000000000000 RDI: ffffffff8fd47960 RBP: 0000000000000000 R08: ffffffff8fd0c47f R09: 1ffffffff1fa188f R10: dffffc0000000000 R11: fffffbfff1fa1890 R12: 0000000000000000 R13: ffff888036d54880 R14: ffff8880609710a0 R15: 0000000000000000 FS: 00007f19ff0b56c0(0000) GS:ffff8881259f2000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff19afa8068 CR3: 0000000043eee000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 000000000000000c DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: cpuhp_invoke_callback+0x498/0x810 kernel/cpu.c:204 cpuhp_issue_call+0x3f0/0x750 kernel/cpu.c:-1 __cpuhp_state_add_instance_cpuslocked+0x225/0x560 kernel/cpu.c:2423 __cpuhp_state_add_instance+0x25/0x40 kernel/cpu.c:2444 cpuhp_state_add_instance include/linux/cpuhotplug.h:384 [inline] alloc_buffer+0x18aa/0x1d50 kernel/trace/ring_buffer.c:2829 __ring_buffer_alloc+0x2c/0x40 kernel/trace/ring_buffer.c:2871 allocate_trace_buffer+0x1d2/0x950 kernel/trace/trace.c:8414 allocate_trace_buffers kernel/trace/trace.c:8447 [inline] trace_array_create_systems+0x590/0xe60 kernel/trace/trace.c:8625 trace_array_create kernel/trace/trace.c:8668 [inline] instance_mkdir+0xd5/0x140 kernel/trace/trace.c:8683 tracefs_syscall_mkdir+0x11a/0x190 fs/tracefs/inode.c:121 vfs_mkdir+0x408/0x620 fs/namei.c:5270 filename_mkdirat+0x289/0x520 fs/namei.c:5303 __do_sys_mkdirat fs/namei.c:5324 [inline] __se_sys_mkdirat+0x35/0x150 fs/namei.c:5321 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x17b/0x530 arch/x86/entry/syscall_64.c:85 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1a00e7e0d9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f19ff0b5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f1a01106090 RCX: 00007f1a00e7e0d9 RDX: 00000000000001ff RSI: 0000200000000700 RDI: ffffffffffffff9c RBP: 00007f1a00f15024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1a01106128 R14: 00007f1a01106090 R15: 00007ffdad82a7e8 ---------------- Code disassembly (best guess): 0: 08 f0 or %dh,%al 2: 48 0f ab 03 bts %rax,(%rbx) 6: 31 c0 xor %eax,%eax 8: 48 83 c4 30 add $0x30,%rsp c: 5b pop %rbx d: 41 5c pop %r12 f: 41 5d pop %r13 11: 41 5e pop %r14 13: 41 5f pop %r15 15: 5d pop %rbp 16: e9 7d 88 8a 09 jmp 0x98a8898 1b: cc int3 1c: e8 87 3b fc ff call 0xfffc3ba8 21: 48 8d 3d 30 11 0b 0e lea 0xe0b1130(%rip),%rdi # 0xe0b1158 28: 89 ee mov %ebp,%esi * 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction 2f: b8 f4 ff ff ff mov $0xfffffff4,%eax 34: eb d2 jmp 0x8 36: e8 6d 3b fc ff call 0xfffc3ba8 3b: e9 ef fe ff ff jmp 0xffffff2f