Re: [syzbot] [fs?] BUG: sleeping function called from invalid context in hook_sb_delete

[syzbot <syzbot+12479ae15958fc3f54ec@syzkaller.appspotmail.com>]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING in get_data

Bluetooth: hci0: unexpected cc 0x0c03 length: 249 > 1
Bluetooth: hci0: unexpected cc 0x1003 length: 249 > 9
------------[ cut here ]------------
WARNING: kernel/printk/printk_ringbuffer.c:1278 at get_data+0x48a/0x840 kernel/printk/printk_ringbuffer.c:1278, CPU#1: kworker/u9:1/5147
Modules linked in:
CPU: 1 UID: 0 PID: 5147 Comm: kworker/u9:1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: hci0 hci_rx_work
RIP: 0010:get_data+0x48a/0x840 kernel/printk/printk_ringbuffer.c:1278
Code: 83 c4 f8 48 b8 00 00 00 00 00 fc ff df 41 0f b6 04 07 84 c0 0f 85 ee 01 00 00 44 89 65 00 49 83 c5 08 eb 13 e8 b7 d6 1e 00 90 <0f> 0b 90 eb 05 e8 ac d6 1e 00 45 31 ed 4c 89 e8 48 83 c4 28 5b 41
RSP: 0018:ffffc9000ed9eec0 EFLAGS: 00010293
RAX: ffffffff81a1ef09 RBX: 00003fffffffffff RCX: ffff888035008000
RDX: 0000000000000000 RSI: 00003fffffffffff RDI: 0000000000000000
RBP: 0000000000000012 R08: 0000000000000ea9 R09: 0000005832e2457e
R10: 0000005832e2457e R11: 0000141b82000035 R12: 0000000000000012
R13: 0000000000000000 R14: ffffc9000ed9f008 R15: 1ffffffff1c0ab06
FS:  0000000000000000(0000) GS:ffff888125dd3000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffea26700c0 CR3: 0000000075b8a000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 copy_data kernel/printk/printk_ringbuffer.c:1857 [inline]
 prb_read kernel/printk/printk_ringbuffer.c:1966 [inline]
 _prb_read_valid+0x672/0xa90 kernel/printk/printk_ringbuffer.c:2143
 prb_read_valid+0x3c/0x60 kernel/printk/printk_ringbuffer.c:2215
 printk_get_next_message+0x15c/0x7b0 kernel/printk/printk.c:2978
 console_emit_next_record kernel/printk/printk.c:3062 [inline]
 console_flush_one_record kernel/printk/printk.c:3194 [inline]
 console_flush_all+0x4cc/0xb10 kernel/printk/printk.c:3268
 __console_flush_and_unlock kernel/printk/printk.c:3298 [inline]
 console_unlock+0xbb/0x190 kernel/printk/printk.c:3338
 vprintk_emit+0x4c5/0x590 kernel/printk/printk.c:2423
 _printk+0xcf/0x120 kernel/printk/printk.c:2448
 bt_warn+0x10b/0x160 net/bluetooth/lib.c:276
 hci_cc_func net/bluetooth/hci_event.c:4192 [inline]
 hci_cmd_complete_evt+0x493/0xa80 net/bluetooth/hci_event.c:4216
 hci_event_func net/bluetooth/hci_event.c:7629 [inline]
 hci_event_packet+0x78f/0x1260 net/bluetooth/hci_event.c:7686
 hci_rx_work+0x45d/0xfc0 net/bluetooth/hci_core.c:4099
 process_one_work+0x94a/0x15d0 kernel/workqueue.c:3267
 process_scheduled_works kernel/workqueue.c:3350 [inline]
 worker_thread+0x9b0/0xee0 kernel/workqueue.c:3431
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>


Tested on:

commit:         98bd8b16 Add linux-next specific files for 20251031
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=12a8e32f980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=90be0b22166ec0b9
dashboard link: https://syzkaller.appspot.com/bug?extid=12479ae15958fc3f54ec
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1430e32f980000