CVE-2022-49111

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

Bluetooth: Fix use after free in hci_send_acl

This fixes the following trace caused by receiving

HCI_EV_DISCONN_PHY_LINK_COMPLETE which does call hci_conn_del without

first checking if conn->type is in fact AMP_LINK and in case it is

do properly cleanup upper layers with hci_disconn_cfm:

==================================================================

BUG: KASAN: use-after-free in hci_send_acl+0xaba/0xc50

Read of size 8 at addr ffff88800e404818 by task bluetoothd/142

CPU: 0 PID: 142 Comm: bluetoothd Not tainted

5.17.0-rc5-00006-gda4022eeac1a #7

Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS

rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014

Call Trace:

<TASK>

dump_stack_lvl+0x45/0x59

print_address_description.constprop.0+0x1f/0x150

kasan_report.cold+0x7f/0x11b

hci_send_acl+0xaba/0xc50

l2cap_do_send+0x23f/0x3d0

l2cap_chan_send+0xc06/0x2cc0

l2cap_sock_sendmsg+0x201/0x2b0

sock_sendmsg+0xdc/0x110

sock_write_iter+0x20f/0x370

do_iter_readv_writev+0x343/0x690

do_iter_write+0x132/0x640

vfs_writev+0x198/0x570

do_writev+0x202/0x280

do_syscall_64+0x38/0x90

entry_SYSCALL_64_after_hwframe+0x44/0xae

RSP: 002b:00007ffce8a099b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000014

Code: 0f 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 f3

0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 14 00 00 00 0f 05

<48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10

RDX: 0000000000000001 RSI: 00007ffce8a099e0 RDI: 0000000000000015

RAX: ffffffffffffffda RBX: 00007ffce8a099e0 RCX: 00007f788fc3cf77

R10: 00007ffce8af7080 R11: 0000000000000246 R12: 000055e4ccf75580

RBP: 0000000000000015 R08: 0000000000000002 R09: 0000000000000001

</TASK>

R13: 000055e4ccf754a0 R14: 000055e4ccf75cd0 R15: 000055e4ccf4a6b0

Allocated by task 45:

kasan_save_stack+0x1e/0x40

__kasan_kmalloc+0x81/0xa0

hci_chan_create+0x9a/0x2f0

l2cap_conn_add.part.0+0x1a/0xdc0

l2cap_connect_cfm+0x236/0x1000

le_conn_complete_evt+0x15a7/0x1db0

hci_le_conn_complete_evt+0x226/0x2c0

hci_le_meta_evt+0x247/0x450

hci_event_packet+0x61b/0xe90

hci_rx_work+0x4d5/0xc50

process_one_work+0x8fb/0x15a0

worker_thread+0x576/0x1240

kthread+0x29d/0x340

ret_from_fork+0x1f/0x30

Freed by task 45:

kasan_save_stack+0x1e/0x40

kasan_set_track+0x21/0x30

kasan_set_free_info+0x20/0x30

__kasan_slab_free+0xfb/0x130

kfree+0xac/0x350

hci_conn_cleanup+0x101/0x6a0

hci_conn_del+0x27e/0x6c0

hci_disconn_phylink_complete_evt+0xe0/0x120

hci_event_packet+0x812/0xe90

hci_rx_work+0x4d5/0xc50

process_one_work+0x8fb/0x15a0

worker_thread+0x576/0x1240

kthread+0x29d/0x340

ret_from_fork+0x1f/0x30

The buggy address belongs to the object at ffff88800c0f0500

The buggy address is located 24 bytes inside of

which belongs to the cache kmalloc-128 of size 128

The buggy address belongs to the page:

128-byte region [ffff88800c0f0500, ffff88800c0f0580)

flags: 0x100000000000200(slab|node=0|zone=1)

page:00000000fe45cd86 refcount:1 mapcount:0

mapping:0000000000000000 index:0x0 pfn:0xc0f0

raw: 0000000000000000 0000000080100010 00000001ffffffff

0000000000000000

raw: 0100000000000200 ffffea00003a2c80 dead000000000004

ffff8880078418c0

page dumped because: kasan: bad access detected

ffff88800c0f0400: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc

Memory state around the buggy address:

>ffff88800c0f0500: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

ffff88800c0f0480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc

ffff88800c0f0580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc

---truncated---