[syzbot] [bluetooth?] KASAN: null-ptr-deref Write in l2cap_sock_resume_cb

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    2c9b3512402e Merge tag 'for-linus' of git://git.kernel.org..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13550ec3980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=be4129de17851dbe
dashboard link: https://syzkaller.appspot.com/bug?extid=52115a16e7eac723d587
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-2c9b3512.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/105004175f16/vmlinux-2c9b3512.xz
kernel image: https://storage.googleapis.com/syzbot-assets/4d8a81aaa129/bzImage-2c9b3512.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+52115a16e7eac723d587@xxxxxxxxxxxxxxxxxxxxxxxxx

Bluetooth: hci2: ISO packet for unknown connection handle 0
==================================================================
BUG: KASAN: null-ptr-deref in instrument_atomic_write include/linux/instrumented.h:82 [inline]
BUG: KASAN: null-ptr-deref in clear_bit include/asm-generic/bitops/instrumented-atomic.h:41 [inline]
BUG: KASAN: null-ptr-deref in l2cap_sock_resume_cb+0xd0/0x130 net/bluetooth/l2cap_sock.c:1697
Write of size 8 at addr 0000000000000518 by task kworker/u33:6/5222

CPU: 1 PID: 5222 Comm: kworker/u33:6 Not tainted 6.10.0-syzkaller-11185-g2c9b3512402e #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: hci0 hci_rx_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
 kasan_report+0xd9/0x110 mm/kasan/report.c:601
 check_region_inline mm/kasan/generic.c:183 [inline]
 kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189
 instrument_atomic_write include/linux/instrumented.h:82 [inline]
 clear_bit include/asm-generic/bitops/instrumented-atomic.h:41 [inline]
 l2cap_sock_resume_cb+0xd0/0x130 net/bluetooth/l2cap_sock.c:1697
 l2cap_security_cfm+0x78d/0x11d0 net/bluetooth/l2cap_core.c:7354
 hci_encrypt_cfm+0x194/0x720 include/net/bluetooth/hci_core.h:2041
 hci_encrypt_change_evt+0x554/0x10f0 net/bluetooth/hci_event.c:3649
 hci_event_func net/bluetooth/hci_event.c:7445 [inline]
 hci_event_packet+0x9eb/0x1180 net/bluetooth/hci_event.c:7497
 hci_rx_work+0x2c6/0x1610 net/bluetooth/hci_core.c:4029
 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xf20 kernel/workqueue.c:3390
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
==================================================================


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