syzbot

Bluetooth: hci0: Opcode 0x1003 failed: -110
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BUG: KCSAN: data-race in data_alloc / data_push_tail

write to 0xffffffff893a5430 of 8 bytes by task 14749 on cpu 0:
 data_alloc+0x259/0x390 kernel/printk/printk_ringbuffer.c:1116
 prb_reserve+0x8d7/0xae0 kernel/printk/printk_ringbuffer.c:1724
 vprintk_store+0x54a/0x910 kernel/printk/printk.c:2354
 vprintk_emit+0x1a4/0x600 kernel/printk/printk.c:2455
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2494
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x79/0xa0 kernel/printk/printk.c:2504
 bt_err+0xa7/0xd0 net/bluetooth/lib.c:296
 hci_cmd_timeout+0x97/0x140 net/bluetooth/hci_core.c:1470
 process_one_work kernel/workqueue.c:3275 [inline]
 process_scheduled_works+0x4de/0x9e0 kernel/workqueue.c:3358
 worker_thread+0x581/0x770 kernel/workqueue.c:3439
 kthread+0x22a/0x280 kernel/kthread.c:467
 ret_from_fork+0x150/0x360 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffffffff893a5430 of 8 bytes by task 4056 on cpu 1:
 data_make_reusable kernel/printk/printk_ringbuffer.c:608 [inline]
 data_push_tail+0x100/0x470 kernel/printk/printk_ringbuffer.c:693
 data_alloc+0x11b/0x390 kernel/printk/printk_ringbuffer.c:1089
 prb_reserve+0x8d7/0xae0 kernel/printk/printk_ringbuffer.c:1724
 vprintk_store+0x54a/0x910 kernel/printk/printk.c:2354
 vprintk_emit+0x1a4/0x600 kernel/printk/printk.c:2455
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2494
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x79/0xa0 kernel/printk/printk.c:2504
 bt_err+0xa7/0xd0 net/bluetooth/lib.c:296
 __hci_cmd_sync_status_sk net/bluetooth/hci_sync.c:271 [inline]
 __hci_cmd_sync_status net/bluetooth/hci_sync.c:287 [inline]
 hci_read_local_features_sync net/bluetooth/hci_sync.c:3708 [inline]
 hci_init_stage_sync net/bluetooth/hci_sync.c:3623 [inline]
 hci_init1_sync net/bluetooth/hci_sync.c:3755 [inline]
 hci_init_sync net/bluetooth/hci_sync.c:4917 [inline]
 hci_dev_init_sync net/bluetooth/hci_sync.c:5109 [inline]
 hci_dev_open_sync+0xfa4/0x2290 net/bluetooth/hci_sync.c:5187
 hci_dev_do_open net/bluetooth/hci_core.c:431 [inline]
 hci_power_on+0xef/0x390 net/bluetooth/hci_core.c:960
 process_one_work kernel/workqueue.c:3275 [inline]
 process_scheduled_works+0x4de/0x9e0 kernel/workqueue.c:3358
 worker_thread+0x581/0x770 kernel/workqueue.c:3439
 kthread+0x22a/0x280 kernel/kthread.c:467
 ret_from_fork+0x150/0x360 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x00000000fffff340 -> 0x00000000fffffe34

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 4056 Comm: kworker/u9:2 Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: hci0 hci_power_on
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