KASAN: use-after-free Read in l2cap_sock_ready

Kernel	Title	Count	Last	Reported	Patched	Status
linux-6.1	KASAN: use-after-free Read in l2cap_sock_ready_cb	1	15d	15d	0/3	upstream: reported on 2024/12/06 13:13
upstream	KASAN: slab-use-after-free Read in l2cap_sock_ready_cb (2) bluetooth	12	9h42m	81d	0/28	upstream: reported on 2024/10/01 10:15
upstream	KASAN: slab-use-after-free Read in l2cap_sock_ready_cb bluetooth	1	208d	204d	0/28	auto-obsoleted due to no activity on 2024/09/04 06:40
kobject_add_internal failed for hci2:201 with -EEXIST, don't try to register things with the same name in the same directory.
Bluetooth: hci2: failed to register connection device
==================================================================
BUG: KASAN: use-after-free in l2cap_sock_ready_cb+0xc4/0x130 net/bluetooth/l2cap_sock.c:1659
Read of size 8 at addr ffff0000dc6874c8 by task kworker/u5:3/4028

CPU: 1 PID: 4028 Comm: kworker/u5:3 Not tainted 5.15.173-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: hci2 hci_rx_work
Call trace:
 dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
 print_address_description+0x7c/0x3f0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0x174/0x1e4 mm/kasan/report.c:451
 __asan_report_load8_noabort+0x44/0x50 mm/kasan/report_generic.c:309
 l2cap_sock_ready_cb+0xc4/0x130 net/bluetooth/l2cap_sock.c:1659
 l2cap_chan_ready net/bluetooth/l2cap_core.c:1385 [inline]
 l2cap_le_start+0x59c/0x19dc net/bluetooth/l2cap_core.c:1497
 l2cap_conn_ready net/bluetooth/l2cap_core.c:1766 [inline]
 l2cap_connect_cfm+0x5a8/0xe5c net/bluetooth/l2cap_core.c:8298
 hci_connect_cfm include/net/bluetooth/hci_core.h:1505 [inline]
 le_conn_complete_evt+0xa30/0x1228 net/bluetooth/hci_event.c:5432
 hci_le_conn_complete_evt net/bluetooth/hci_event.c:5457 [inline]
 hci_le_meta_evt+0x234/0x31c0 net/bluetooth/hci_event.c:6178
 hci_event_packet+0xd34/0x12b4 net/bluetooth/hci_event.c:6527
 hci_rx_work+0x1c0/0x7c4 net/bluetooth/hci_core.c:5155
 process_one_work+0x790/0x11b8 kernel/workqueue.c:2310
 worker_thread+0x910/0x1034 kernel/workqueue.c:2457
 kthread+0x37c/0x45c kernel/kthread.c:334
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870

Allocated by task 5905:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc+0xbc/0xfc mm/kasan/common.c:513
 __kasan_kmalloc+0x10/0x1c mm/kasan/common.c:522
 kasan_kmalloc include/linux/kasan.h:264 [inline]
 __kmalloc+0x29c/0x4c8 mm/slub.c:4407
 kmalloc include/linux/slab.h:596 [inline]
 sk_prot_alloc+0xc4/0x1f0 net/core/sock.c:1863
 sk_alloc+0x40/0x3e0 net/core/sock.c:1916
 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1861 [inline]
 l2cap_sock_create+0x140/0x33c net/bluetooth/l2cap_sock.c:1907
 bt_sock_create+0x14c/0x248 net/bluetooth/af_bluetooth.c:130
 __sock_create+0x43c/0x8a0 net/socket.c:1486
 sock_create net/socket.c:1542 [inline]
 __sys_socket+0x168/0x310 net/socket.c:1584
 __do_sys_socket net/socket.c:1593 [inline]
 __se_sys_socket net/socket.c:1591 [inline]
 __arm64_sys_socket+0x7c/0x94 net/socket.c:1591
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

Freed by task 5905:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4c/0x84 mm/kasan/common.c:46
 kasan_set_free_info+0x28/0x4c mm/kasan/generic.c:360
 ____kasan_slab_free+0x118/0x164 mm/kasan/common.c:366
 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:374
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1705 [inline]
 slab_free_freelist_hook+0x128/0x1ec mm/slub.c:1731
 slab_free mm/slub.c:3499 [inline]
 kfree+0x178/0x410 mm/slub.c:4559
 sk_prot_free net/core/sock.c:1899 [inline]
 __sk_destruct+0x418/0x600 net/core/sock.c:1985
 sk_destruct net/core/sock.c:2000 [inline]
 __sk_free+0x37c/0x4e8 net/core/sock.c:2011
 sk_free+0x68/0xdc net/core/sock.c:2022
 sock_put include/net/sock.h:1923 [inline]
 l2cap_sock_kill+0x114/0x228 net/bluetooth/l2cap_sock.c:1258
 l2cap_sock_release+0x138/0x1b4 net/bluetooth/l2cap_sock.c:1429
 __sock_release net/socket.c:649 [inline]
 sock_close+0xb8/0x1fc net/socket.c:1336
 __fput+0x1c4/0x800 fs/file_table.c:280
 ____fput+0x20/0x30 fs/file_table.c:308
 task_work_run+0x130/0x1e4 kernel/task_work.c:188
 exit_task_work include/linux/task_work.h:33 [inline]
 do_exit+0x670/0x20bc kernel/exit.c:874
 do_group_exit+0x110/0x268 kernel/exit.c:996
 get_signal+0x634/0x1550 kernel/signal.c:2900
 do_signal arch/arm64/kernel/signal.c:890 [inline]
 do_notify_resume+0x3d0/0x32b8 arch/arm64/kernel/signal.c:943
 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:133 [inline]
 exit_to_user_mode arch/arm64/kernel/entry-common.c:138 [inline]
 el0_svc+0xfc/0x1f0 arch/arm64/kernel/entry-common.c:609
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

Last potentially related work creation:
 kasan_save_stack+0x38/0x68 mm/kasan/common.c:38
 kasan_record_aux_stack+0xd4/0x11c mm/kasan/generic.c:348
 kvfree_call_rcu+0xb8/0x684 kernel/rcu/tree.c:3596
 drop_sysctl_table+0x274/0x3a0 fs/proc/proc_sysctl.c:1678
 unregister_sysctl_table+0x94/0x130 fs/proc/proc_sysctl.c:1716
 unregister_net_sysctl_table+0x20/0x30 net/sysctl_net.c:175
 __devinet_sysctl_unregister net/ipv4/devinet.c:2626 [inline]
 devinet_sysctl_unregister net/ipv4/devinet.c:2654 [inline]
 inetdev_destroy net/ipv4/devinet.c:326 [inline]
 inetdev_event+0x534/0x1234 net/ipv4/devinet.c:1611
 notifier_call_chain kernel/notifier.c:83 [inline]
 raw_notifier_call_chain+0xd4/0x164 kernel/notifier.c:391
 call_netdevice_notifiers_info net/core/dev.c:2018 [inline]
 call_netdevice_notifiers_extack net/core/dev.c:2030 [inline]
 call_netdevice_notifiers net/core/dev.c:2044 [inline]
 unregister_netdevice_many+0xec4/0x189c net/core/dev.c:11102
 default_device_exit_batch+0x4c0/0x520 net/core/dev.c:11635
 ops_exit_list net/core/net_namespace.c:177 [inline]
 cleanup_net+0x5e0/0x9bc net/core/net_namespace.c:599
 process_one_work+0x790/0x11b8 kernel/workqueue.c:2310
 worker_thread+0x910/0x1034 kernel/workqueue.c:2457
 kthread+0x37c/0x45c kernel/kthread.c:334
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870

The buggy address belongs to the object at ffff0000dc687000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1224 bytes inside of
 2048-byte region [ffff0000dc687000, ffff0000dc687800)
The buggy address belongs to the page:
page:00000000caabca20 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11c680
head:00000000caabca20 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000010200 0000000000000000 0000000100000001 ffff0000c0002900
raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000dc687380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff0000dc687400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff0000dc687480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                              ^
 ffff0000dc687500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff0000dc687580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================