------------[ cut here ]------------ failed to allocate ring buffer on CPU 0 WARNING: kernel/trace/ring_buffer.c:7976 at trace_rb_cpu_prepare+0x458/0x500 kernel/trace/ring_buffer.c:7976, CPU#0: syz.5.1721/13466 Modules linked in: CPU: 0 UID: 0 PID: 13466 Comm: syz.5.1721 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:trace_rb_cpu_prepare+0x45a/0x500 kernel/trace/ring_buffer.c:7976 Code: 48 c1 ea 03 80 3c 02 00 0f 84 c7 fc ff ff 48 8b 3c 24 e8 89 16 6b 00 e9 b9 fc ff ff e8 ff 83 fb ff 48 8d 3d 98 08 18 0f 89 ee <67> 48 0f b9 3a bb f4 ff ff ff e9 df fd ff ff 4c 89 ef e8 5f 16 6b RSP: 0018:ffffc900089f78c0 EFLAGS: 00010283 RAX: 00000000000140d9 RBX: ffff88807a38acb8 RCX: ffffc90006101000 RDX: 0000000000080000 RSI: 0000000000000000 RDI: ffffffff9126d860 RBP: 0000000000000000 R08: ffff88807cef9a80 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 R13: ffff88807a38ac10 R14: 0000000000000000 R15: 0000000000000162 FS: 00007f871e3246c0(0000) GS:ffff888123dd9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005571b2d68be0 CR3: 0000000046d68000 CR4: 0000000000350ef0 Call Trace: cpuhp_invoke_callback+0x205/0x9a0 kernel/cpu.c:204 cpuhp_issue_call+0x1b8/0x970 kernel/cpu.c:2354 __cpuhp_state_add_instance_cpuslocked+0x2d7/0x400 kernel/cpu.c:2423 __cpuhp_state_add_instance+0xd7/0x2d0 kernel/cpu.c:2444 cpuhp_state_add_instance include/linux/cpuhotplug.h:384 [inline] alloc_buffer+0x76c/0x1800 kernel/trace/ring_buffer.c:2830 __ring_buffer_alloc+0x2d/0x40 kernel/trace/ring_buffer.c:2872 allocate_trace_buffer+0x150/0xa30 kernel/trace/trace.c:8412 allocate_trace_buffers kernel/trace/trace.c:8445 [inline] trace_array_create_systems+0x582/0xc30 kernel/trace/trace.c:8623 trace_array_create kernel/trace/trace.c:8666 [inline] instance_mkdir+0xca/0x140 kernel/trace/trace.c:8681 tracefs_syscall_mkdir+0x10e/0x180 fs/tracefs/inode.c:121 vfs_mkdir+0x361/0x850 fs/namei.c:5276 filename_mkdirat+0x48b/0x5e0 fs/namei.c:5309 __do_sys_mkdirat fs/namei.c:5330 [inline] __se_sys_mkdirat fs/namei.c:5327 [inline] __x64_sys_mkdirat+0x89/0xc0 fs/namei.c:5327 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f871d39e019 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:00007f871e324028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f871d625fa0 RCX: 00007f871d39e019 RDX: 00000000000001ff RSI: 0000200000000200 RDI: ffffffffffffff9c RBP: 00007f871d43500c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f871d626038 R14: 00007f871d625fa0 R15: 00007fff3dc1ca98 ---------------- Code disassembly (best guess): 0: 48 c1 ea 03 shr $0x3,%rdx 4: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) 8: 0f 84 c7 fc ff ff je 0xfffffcd5 e: 48 8b 3c 24 mov (%rsp),%rdi 12: e8 89 16 6b 00 call 0x6b16a0 17: e9 b9 fc ff ff jmp 0xfffffcd5 1c: e8 ff 83 fb ff call 0xfffb8420 21: 48 8d 3d 98 08 18 0f lea 0xf180898(%rip),%rdi # 0xf1808c0 28: 89 ee mov %ebp,%esi * 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction 2f: bb f4 ff ff ff mov $0xfffffff4,%ebx 34: e9 df fd ff ff jmp 0xfffffe18 39: 4c 89 ef mov %r13,%rdi 3c: e8 .byte 0xe8 3d: 5f pop %rdi 3e: 16 (bad) 3f: 6b .byte 0x6b