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BUG: KASAN: slab-use-after-free in hci_send_acl+0x54/0xc48 net/bluetooth/hci_core.c:3231
Read of size 8 at addr ffff0000da1c2418 by task kworker/1:6/6186

CPU: 1 PID: 6186 Comm: kworker/1:6 Not tainted 6.6.0-rc7-syzkaller-g8de1e7afcc1c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
Workqueue: events l2cap_info_timeout
Call trace:
 dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:233
 show_stack+0x2c/0x44 arch/arm64/kernel/stacktrace.c:240
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0x174/0x514 mm/kasan/report.c:475
 kasan_report+0xd8/0x138 mm/kasan/report.c:588
 __asan_report_load8_noabort+0x20/0x2c mm/kasan/report_generic.c:381
 hci_send_acl+0x54/0xc48 net/bluetooth/hci_core.c:3231
 l2cap_send_cmd+0x52c/0x76c net/bluetooth/l2cap_core.c:977
 l2cap_send_conn_req+0x188/0x2c4 net/bluetooth/l2cap_core.c:1286
 l2cap_start_connection+0x118/0x2fc net/bluetooth/l2cap_core.c:1514
 l2cap_conn_start+0x928/0xd8c net/bluetooth/l2cap_core.c:1661
 l2cap_info_timeout+0x68/0xb8 net/bluetooth/l2cap_core.c:1807
 process_one_work+0x694/0x1204 kernel/workqueue.c:2630
 process_scheduled_works kernel/workqueue.c:2703 [inline]
 worker_thread+0x938/0xef4 kernel/workqueue.c:2784
 kthread+0x288/0x310 kernel/kthread.c:388
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:857

Allocated by task 6505:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4c/0x7c mm/kasan/common.c:52
 kasan_save_alloc_info+0x24/0x30 mm/kasan/generic.c:511
 ____kasan_kmalloc mm/kasan/common.c:374 [inline]
 __kasan_kmalloc+0xac/0xc4 mm/kasan/common.c:383
 kasan_kmalloc include/linux/kasan.h:198 [inline]
 kmalloc_trace+0x70/0x88 mm/slab_common.c:1122
 kmalloc include/linux/slab.h:599 [inline]
 kzalloc include/linux/slab.h:720 [inline]
 hci_chan_create+0xb0/0x2b0 net/bluetooth/hci_conn.c:2723
 l2cap_conn_add+0x78/0x998 net/bluetooth/l2cap_core.c:7841
 l2cap_chan_connect+0x5bc/0xce4 net/bluetooth/l2cap_core.c:8053
 bt_6lowpan_connect net/bluetooth/6lowpan.c:894 [inline]
 lowpan_control_write+0x4e8/0x824 net/bluetooth/6lowpan.c:1129
 full_proxy_write+0x110/0x1f8 fs/debugfs/file.c:236
 vfs_write+0x2a0/0x93c fs/read_write.c:582
 ksys_write+0x15c/0x26c fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:646
 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
 el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595

The buggy address belongs to the object at ffff0000da1c2400
 which belongs to the cache kmalloc-128 of size 128
The buggy address is located 24 bytes inside of
 freed 128-byte region [ffff0000da1c2400, ffff0000da1c2480)

The buggy address belongs to the physical page:
page:000000008bcc908e refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff0000da1c2400 pfn:0x11a1c2
flags: 0x5ffc00000000800(slab|node=0|zone=2|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 05ffc00000000800 ffff0000c00018c0 fffffc00033a0750 fffffc00032dcd90
raw: ffff0000da1c2400 0000000000100003 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000da1c2300: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc
 ffff0000da1c2380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff0000da1c2400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff0000da1c2480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff0000da1c2500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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