WARNING in trace_rb_cpu_prepare

Status: upstream: reported syz repro on 2026/08/03 11:32
Subsystems: trace
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+fbe07bcf949966f3c00f@syzkaller.appspotmail.com
First crash: 22d, last: 29m
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
e96a8265 assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ WARNING in trace_rb_cpu_prepare 2026/08/01 00:00 2026/08/01 00:00 2026/08/01 00:26 7664cf44
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [trace?] WARNING in trace_rb_cpu_prepare 1 (3) 2026/08/06 21:46
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-6-12 WARNING in trace_rb_cpu_prepare -1 5 4d18h 20d 0/1 premoderation: reported on 2026/08/01 06:47
linux-5.15 WARNING in trace_rb_cpu_prepare -1 8 18h54m 20d 0/3 upstream: reported on 2026/08/01 23:00
linux-6.6 WARNING in trace_rb_cpu_prepare -1 syz, C 8 4h34m 20d 0/2 upstream: reported C repro on 2026/08/01 09:59
linux-6.1 WARNING in trace_rb_cpu_prepare -1 9 3h23m 13d 0/3 upstream: reported on 2026/08/08 09:55
Cause bisection attempts (1)
Created Duration User Patch Repo Result
2026/08/09 14:24 0m bisect upstream error

Sample crash report:
------------[ cut here ]------------
failed to allocate ring buffer on CPU 1
WARNING: kernel/trace/ring_buffer.c:7979 at trace_rb_cpu_prepare+0x458/0x500 kernel/trace/ring_buffer.c:7979, CPU#0: syz.3.34/6130
Modules linked in:
CPU: 0 UID: 0 PID: 6130 Comm: syz.3.34 Not tainted syzkaller #0 PREEMPT(full) 
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:7979
Code: 48 c1 ea 03 80 3c 02 00 0f 84 c7 fc ff ff 48 8b 3c 24 e8 89 1a 6b 00 e9 b9 fc ff ff e8 5f 83 fb ff 48 8d 3d 78 05 17 0f 89 ee <67> 48 0f b9 3a bb f4 ff ff ff e9 df fd ff ff 4c 89 ef e8 5f 1a 6b
RSP: 0018:ffffc900043678c0 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff88807bcaf0b8 RCX: ffff888071512088
RDX: ffff8880237c5d00 RSI: 0000000000000001 RDI: ffffffff9125e480
RBP: 0000000000000001 R08: ffff888071512088 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001
R13: ffff88807bcaf010 R14: 0000000000000008 R15: 0000000000000162
FS:  00007f9c754cf6c0(0000) GS:ffff888123dec000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000004b000 CR3: 00000000775c1000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 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:2833
 __ring_buffer_alloc+0x2d/0x40 kernel/trace/ring_buffer.c:2875
 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: 0033:0x7f9c7459e0d9
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:00007f9c754cf028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f9c74825fa0 RCX: 00007f9c7459e0d9
RDX: 00000000000001ff RSI: 0000200000000140 RDI: ffffffffffffff9c
RBP: 00007f9c74635024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9c74826038 R14: 00007f9c74825fa0 R15: 00007fff55700368
 </TASK>
----------------
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 1a 6b 00       	call   0x6b1aa0
  17:	e9 b9 fc ff ff       	jmp    0xfffffcd5
  1c:	e8 5f 83 fb ff       	call   0xfffb8380
  21:	48 8d 3d 78 05 17 0f 	lea    0xf170578(%rip),%rdi        # 0xf1705a0
  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:	1a                   	.byte 0x1a
  3f:	6b                   	.byte 0x6b

Crashes (1018):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/11 22:22 upstream d58772d8520c 37a258dd .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in trace_rb_cpu_prepare
2026/08/06 07:37 upstream 0d8395707651 cd5b1963 .config strace log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci2-upstream-fs WARNING in trace_rb_cpu_prepare
2026/08/06 06:38 upstream 0d8395707651 cd5b1963 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in trace_rb_cpu_prepare
2026/08/19 23:42 upstream bd5f485f3f02 1e72964b .config console log report syz / log [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in trace_rb_cpu_prepare
2026/08/21 22:43 upstream 531ed942bb0d 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in trace_rb_cpu_prepare
2026/08/21 19:57 upstream 818bebeb63dd 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in trace_rb_cpu_prepare
2026/08/21 17:36 upstream 818bebeb63dd 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in trace_rb_cpu_prepare
2026/08/21 16:18 upstream 818bebeb63dd 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in trace_rb_cpu_prepare
2026/08/21 16:16 upstream 818bebeb63dd 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in trace_rb_cpu_prepare
2026/08/21 15:06 upstream 818bebeb63dd 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in trace_rb_cpu_prepare
2026/08/21 12:55 upstream 7f063b2f17ea 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in trace_rb_cpu_prepare
2026/08/21 09:24 upstream 7f063b2f17ea 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in trace_rb_cpu_prepare
2026/08/21 07:46 upstream 7f063b2f17ea 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in trace_rb_cpu_prepare
2026/08/21 05:25 upstream 91ec20351349 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in trace_rb_cpu_prepare
2026/08/21 04:20 upstream 7f063b2f17ea 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in trace_rb_cpu_prepare
2026/08/21 00:41 upstream a4ff2be345d0 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in trace_rb_cpu_prepare
2026/08/20 23:29 upstream a4ff2be345d0 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in trace_rb_cpu_prepare
2026/08/20 20:01 upstream a4ff2be345d0 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in trace_rb_cpu_prepare
2026/08/20 19:00 upstream a4ff2be345d0 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in trace_rb_cpu_prepare
2026/08/20 18:57 upstream a4ff2be345d0 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in trace_rb_cpu_prepare
2026/08/20 17:50 upstream a4ff2be345d0 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in trace_rb_cpu_prepare
2026/08/20 16:39 upstream a4ff2be345d0 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in trace_rb_cpu_prepare
2026/08/20 16:13 upstream f4cdf7ca9a1f 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in trace_rb_cpu_prepare
2026/08/20 15:09 upstream a4ff2be345d0 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in trace_rb_cpu_prepare
2026/08/20 14:01 upstream a4ff2be345d0 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in trace_rb_cpu_prepare
2026/08/20 10:31 upstream f4cdf7ca9a1f 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in trace_rb_cpu_prepare
2026/08/20 07:35 upstream a4ff2be345d0 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in trace_rb_cpu_prepare
2026/08/20 05:04 upstream e8bf40d15402 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in trace_rb_cpu_prepare
2026/08/20 01:29 upstream 98f21c54f995 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in trace_rb_cpu_prepare
2026/08/19 08:26 upstream bd5f485f3f02 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in trace_rb_cpu_prepare
2026/08/18 21:59 upstream 0f23d56f17fd 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in trace_rb_cpu_prepare
2026/08/03 11:29 upstream 075b74841bd0 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in trace_rb_cpu_prepare
2026/07/31 20:11 upstream 8ba098e6b6ff 7664cf44 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in trace_rb_cpu_prepare
2026/07/30 11:27 upstream 11028ab62899 2377cd3d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in trace_rb_cpu_prepare
2026/08/21 06:28 upstream 9d2ed026f031 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in trace_rb_cpu_prepare
2026/08/21 03:48 upstream 9d2ed026f031 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in trace_rb_cpu_prepare
2026/08/21 01:53 upstream 9d2ed026f031 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in trace_rb_cpu_prepare
2026/08/20 22:27 upstream 9d2ed026f031 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in trace_rb_cpu_prepare
2026/08/20 09:18 upstream a4ff2be345d0 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in trace_rb_cpu_prepare
2026/08/19 01:04 upstream 0f23d56f17fd 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in trace_rb_cpu_prepare
2026/08/20 02:58 upstream bd5f485f3f02 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in trace_rb_cpu_prepare
2026/08/19 14:22 upstream b126f6f5940f 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in trace_rb_cpu_prepare
2026/08/19 12:40 upstream b126f6f5940f 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in trace_rb_cpu_prepare
2026/08/19 10:34 upstream b126f6f5940f 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in trace_rb_cpu_prepare
2026/08/19 03:14 upstream b126f6f5940f 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in trace_rb_cpu_prepare
2026/08/21 18:49 linux-next 903c1cf6dff9 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in trace_rb_cpu_prepare
2026/08/21 11:50 linux-next 7079a12d7506 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in trace_rb_cpu_prepare
2026/08/21 10:38 linux-next 7079a12d7506 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in trace_rb_cpu_prepare
2026/08/20 21:06 linux-next 7079a12d7506 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in trace_rb_cpu_prepare
2026/08/20 12:22 linux-next 6a746cd265ae 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in trace_rb_cpu_prepare
2026/08/19 18:17 linux-next 6a746cd265ae 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in trace_rb_cpu_prepare
2026/08/19 16:59 linux-next 6a746cd265ae 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in trace_rb_cpu_prepare
2026/08/19 15:26 linux-next 6a746cd265ae 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in trace_rb_cpu_prepare
2026/08/19 09:40 linux-next 5453bc3279e9 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in trace_rb_cpu_prepare
2026/08/19 06:59 linux-next 5453bc3279e9 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in trace_rb_cpu_prepare
2026/08/19 00:03 linux-next 5453bc3279e9 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in trace_rb_cpu_prepare
2026/08/19 05:42 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 21d6ac051080 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in trace_rb_cpu_prepare
2026/08/20 08:58 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 8da45c93dfa9 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 WARNING in trace_rb_cpu_prepare
2026/08/20 03:37 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 8da45c93dfa9 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 WARNING in trace_rb_cpu_prepare
2026/08/19 23:32 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 8da45c93dfa9 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 WARNING in trace_rb_cpu_prepare
2026/08/19 21:19 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 8da45c93dfa9 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 WARNING in trace_rb_cpu_prepare
* Struck through repros no longer work on HEAD.