==================================================================
BUG: KASAN: global-out-of-bounds in __mutex_lock_common kernel/locking/mutex.c:577 [inline]
BUG: KASAN: global-out-of-bounds in __mutex_lock+0xcb2/0x10b0 kernel/locking/mutex.c:760
Read of size 8 at addr ffffffff8bf38cb0 by task syz.1.2565/18738

CPU: 0 UID: 0 PID: 18738 Comm: syz.1.2565 Not tainted 6.17.0-rc1-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xcd/0x630 mm/kasan/report.c:482
 kasan_report+0xe0/0x110 mm/kasan/report.c:595
 __mutex_lock_common kernel/locking/mutex.c:577 [inline]
 __mutex_lock+0xcb2/0x10b0 kernel/locking/mutex.c:760
 hci_devcd_register+0x47/0x170 net/bluetooth/coredump.c:433
 force_devcd_write+0x16c/0x340 drivers/bluetooth/hci_vhci.c:346
 full_proxy_write+0x12e/0x1a0 fs/debugfs/file.c:388
 vfs_write+0x29d/0x11d0 fs/read_write.c:684
 ksys_write+0x12a/0x250 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7feb17b8ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007feb18a0f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007feb17db5fa0 RCX: 00007feb17b8ebe9
RDX: 000000000000000e RSI: 0000000000000000 RDI: 0000000000000005
RBP: 00007feb17c11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007feb17db6038 R14: 00007feb17db5fa0 R15: 00007ffee5f2ab98
 </TASK>

The buggy address belongs to the variable:
 afs_rxrpc_callback_ops+0x50/0x1560

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xbf38
flags: 0xfff00000002000(reserved|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000002000 ffffea00002fce08 ffffea00002fce08 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner info is not present (never set?)

Memory state around the buggy address:
 ffffffff8bf38b80: 00 00 00 00 f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9
 ffffffff8bf38c00: 00 00 00 00 00 00 00 00 f9 f9 f9 f9 00 00 00 00
>ffffffff8bf38c80: f9 f9 f9 f9 00 00 02 f9 f9 f9 f9 f9 00 00 00 00
                                     ^
 ffffffff8bf38d00: 00 05 f9 f9 f9 f9 f9 f9 00 00 00 00 00 02 f9 f9
 ffffffff8bf38d80: f9 f9 f9 f9 00 00 00 03 f9 f9 f9 f9 00 00 00 00
==================================================================