syzbot
WARNING in trace_rb_cpu_prepare
Status:
premoderation: reported on 2026/08/01 06:47
Reported-by: syzbot+38042c3b24f5bed93c44@syzkaller.appspotmail.com
First crash: 5d13h, last: 5d12h
Sample crash report:
------------[ cut here ]------------
failed to allocate ring buffer on CPU 1
WARNING: CPU: 1 PID: 6078 at kernel/trace/ring_buffer.c:7702 trace_rb_cpu_prepare+0x2c2/0x2f0 kernel/trace/ring_buffer.c:7701
Modules linked in:
CPU: 1 UID: 0 PID: 6078 Comm: syz.8.1786 Not tainted syzkaller #0 200dea8a17c83f35b0a1e1238c384757fc17b797
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:trace_rb_cpu_prepare+0x2c2/0x2f0 kernel/trace/ring_buffer.c:7701
Code: 31 c0 48 83 c4 38 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc e8 0d df fc ff 48 c7 c7 e0 b0 2f 86 8b 75 d4 e8 2e b7 79 ff <0f> 0b b8 f4 ff ff ff eb cf e8 f0 de fc ff e9 33 ff ff ff 66 2e 0f
RSP: 0018:ffffc90001d57848 EFLAGS: 00010246
RAX: 467ecf13fddf1900 RBX: ffff88813928c410 RCX: ffff88811ba23900
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002
RBP: ffffc90001d578a8 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff520003aae6c R12: 0000000000000000
R13: ffff888114008988 R14: ffff888114008988 R15: ffff88813928c450
FS: 00007f6fc81ca6c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000011dedc000 CR4: 00000000003526b0
DR0: 0000000000000000 DR1: 00000000e88ba5cb DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
cpuhp_invoke_callback+0x699/0xf90 kernel/cpu.c:204
cpuhp_issue_call+0x3c4/0x710 kernel/cpu.c:-1
__cpuhp_state_add_instance_cpuslocked+0x178/0x470 kernel/cpu.c:2432
__cpuhp_state_add_instance+0xbf/0x190 kernel/cpu.c:2453
cpuhp_state_add_instance include/linux/cpuhotplug.h:385 [inline]
alloc_buffer+0x14f3/0x1aa0 kernel/trace/ring_buffer.c:2639
__ring_buffer_alloc+0x61/0x120 kernel/trace/ring_buffer.c:2684
allocate_trace_buffer kernel/trace/trace.c:9631 [inline]
allocate_trace_buffers+0x2cc/0xb40 kernel/trace/trace.c:9664
trace_array_create_systems+0x385/0xe80 kernel/trace/trace.c:9827
trace_array_create kernel/trace/trace.c:9867 [inline]
instance_mkdir+0xde/0x130 kernel/trace/trace.c:9882
tracefs_syscall_mkdir+0xaa/0xe0 fs/tracefs/inode.c:139
vfs_mkdir+0x58e/0x810 fs/namei.c:4265
do_mkdirat+0x240/0x530 fs/namei.c:4288
__do_sys_mkdirat fs/namei.c:4303 [inline]
__se_sys_mkdirat fs/namei.c:4301 [inline]
__x64_sys_mkdirat+0x8b/0xa0 fs/namei.c:4301
x64_sys_call+0x2ba8/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:259
do_syscall_x64 arch/x86/entry/common.c:47 [inline]
do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f6fc739e019
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:00007f6fc81ca028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f6fc7625fa0 RCX: 00007f6fc739e019
RDX: 00000000000001ff RSI: 0000200000000140 RDI: ffffffffffffff9c
RBP: 00007f6fc743500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6fc7626038 R14: 00007f6fc7625fa0 R15: 00007fffff8cce48
</TASK>
---[ end trace 0000000000000000 ]---
* Struck through repros no longer work on HEAD.