CVE-2024-49950

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: L2CAP: Fix uaf in l2cap_connect

[Syzbot reported]

BUG: KASAN: slab-use-after-free in l2cap_connect.constprop.0+0x10d8/0x1270 net/bluetooth/l2cap_core.c:3949

Read of size 8 at addr ffff8880241e9800 by task kworker/u9:0/54

CPU: 0 UID: 0 PID: 54 Comm: kworker/u9:0 Not tainted 6.11.0-rc6-syzkaller-00268-g788220eee30d #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024

Workqueue: hci2 hci_rx_work

Call Trace:

<TASK>

__dump_stack lib/dump_stack.c:93 [inline]

dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119

print_address_description mm/kasan/report.c:377 [inline]

print_report+0xc3/0x620 mm/kasan/report.c:488

kasan_report+0xd9/0x110 mm/kasan/report.c:601

l2cap_connect.constprop.0+0x10d8/0x1270 net/bluetooth/l2cap_core.c:3949

l2cap_connect_req net/bluetooth/l2cap_core.c:4080 [inline]

l2cap_bredr_sig_cmd net/bluetooth/l2cap_core.c:4772 [inline]

l2cap_sig_channel net/bluetooth/l2cap_core.c:5543 [inline]

l2cap_recv_frame+0xf0b/0x8eb0 net/bluetooth/l2cap_core.c:6825

l2cap_recv_acldata+0x9b4/0xb70 net/bluetooth/l2cap_core.c:7514

hci_acldata_packet net/bluetooth/hci_core.c:3791 [inline]

hci_rx_work+0xaab/0x1610 net/bluetooth/hci_core.c:4028

process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231

process_scheduled_works kernel/workqueue.c:3312 [inline]

worker_thread+0x6c8/0xed0 kernel/workqueue.c:3389

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

...

Freed by task 5245:

kasan_save_stack+0x33/0x60 mm/kasan/common.c:47

kasan_save_track+0x14/0x30 mm/kasan/common.c:68

kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579

poison_slab_object+0xf7/0x160 mm/kasan/common.c:240

__kasan_slab_free+0x32/0x50 mm/kasan/common.c:256

kasan_slab_free include/linux/kasan.h:184 [inline]

slab_free_hook mm/slub.c:2256 [inline]

slab_free mm/slub.c:4477 [inline]

kfree+0x12a/0x3b0 mm/slub.c:4598

l2cap_conn_free net/bluetooth/l2cap_core.c:1810 [inline]

kref_put include/linux/kref.h:65 [inline]

l2cap_conn_put net/bluetooth/l2cap_core.c:1822 [inline]

l2cap_conn_del+0x59d/0x730 net/bluetooth/l2cap_core.c:1802

l2cap_connect_cfm+0x9e6/0xf80 net/bluetooth/l2cap_core.c:7241

hci_connect_cfm include/net/bluetooth/hci_core.h:1960 [inline]

hci_conn_failed+0x1c3/0x370 net/bluetooth/hci_conn.c:1265

hci_abort_conn_sync+0x75a/0xb50 net/bluetooth/hci_sync.c:5583

abort_conn_sync+0x197/0x360 net/bluetooth/hci_conn.c:2917

hci_cmd_sync_work+0x1a4/0x410 net/bluetooth/hci_sync.c:328

process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231

process_scheduled_works kernel/workqueue.c:3312 [inline]

worker_thread+0x6c8/0xed0 kernel/workqueue.c:3389

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