Hello, syzbot found the following issue on:
HEAD commit: 075b74841bd0 Linux 7.2-rc6 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=16368cc6580000 kernel config: https://syzkaller.appspot.com/x/.config?x=cb17729fb04b1e3a dashboard link: https://syzkaller.appspot.com/bug?extid=fbe07bcf949966f3c00f compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/678e77cc37b9/disk-075b7484.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/cc9f771e7069/vmlinux-075b7484.xz kernel image: https://storage.googleapis.com/syzbot-assets/71a5d4620b85/bzImage-075b7484.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: [email protected] ------------[ cut here ]------------ failed to allocate ring buffer on CPU 0 WARNING: kernel/trace/ring_buffer.c:7977 at trace_rb_cpu_prepare+0x330/0x3c0 kernel/trace/ring_buffer.c:7976, CPU#0: syz.5.14324/5698 Modules linked in: CPU: 0 UID: 0 PID: 5698 Comm: syz.5.14324 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:7976 Code: 08 f0 48 0f ab 03 31 c0 48 83 c4 30 5b 41 5c 41 5d 41 5e 41 5f 5d e9 bd 2f 7e 09 cc e8 17 3b fc ff 48 8d 3d 70 05 ea 0d 89 ee <67> 48 0f b9 3a b8 f4 ff ff ff eb d2 e8 fd 3a fc ff e9 ef fe ff ff RSP: 0018:ffffc90003ddf7e0 EFLAGS: 00010283 RAX: ffffffff81c9a0a9 RBX: dffffc0000000000 RCX: 0000000000080000 RDX: ffffc900125d3000 RSI: 0000000000000000 RDI: ffffffff8fb3a620 RBP: 0000000000000000 R08: ffffffff8fafa337 R09: 1ffffffff1f5f466 R10: dffffc0000000000 R11: fffffbfff1f5f467 R12: 0000000000000000 R13: ffff888025cfb380 R14: ffff88803896c0a0 R15: 0000000000000000 FS: 00007f467e1856c0(0000) GS:ffff888125c3e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f582bc58658 CR3: 0000000075292000 CR4: 00000000003526f0 Call Trace: <TASK> 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:2830 __ring_buffer_alloc+0x2c/0x40 kernel/trace/ring_buffer.c:2872 allocate_trace_buffer+0x1d2/0x950 kernel/trace/trace.c:8412 allocate_trace_buffers kernel/trace/trace.c:8445 [inline] trace_array_create_systems+0x590/0xe60 kernel/trace/trace.c:8623 trace_array_create kernel/trace/trace.c:8666 [inline] instance_mkdir+0xd5/0x140 kernel/trace/trace.c:8681 tracefs_syscall_mkdir+0x11a/0x190 fs/tracefs/inode.c:121 vfs_mkdir+0x402/0x620 fs/namei.c:5276 filename_mkdirat+0x289/0x520 fs/namei.c:5309 __do_sys_mkdirat fs/namei.c:5330 [inline] __se_sys_mkdirat+0x35/0x150 fs/namei.c:5327 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f467ff4e019 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:00007f467e185028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f46801d6090 RCX: 00007f467ff4e019 RDX: 00000000000001ff RSI: 0000200000000200 RDI: ffffffffffffff9c RBP: 00007f467ffe500c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f46801d6128 R14: 00007f46801d6090 R15: 00007fffce30c118 </TASK> ---------------- 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 bd 2f 7e 09 jmp 0x97e2fd8 1b: cc int3 1c: e8 17 3b fc ff call 0xfffc3b38 21: 48 8d 3d 70 05 ea 0d lea 0xdea0570(%rip),%rdi # 0xdea0598 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 fd 3a fc ff call 0xfffc3b38 3b: e9 ef fe ff ff jmp 0xffffff2f --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at [email protected]. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
