CVE-2024-36968

Bluetooth: L2CAP: Fix div-by-zero in l2cap_le_flowctl_init()

Severity Score

6.5

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

Track

*SSVC

Descriptions

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

Bluetooth: L2CAP: Fix div-by-zero in l2cap_le_flowctl_init()

l2cap_le_flowctl_init() can cause both div-by-zero and an integer
overflow since hdev->le_mtu may not fall in the valid range.

Move MTU from hci_dev to hci_conn to validate MTU and stop the connection
process earlier if MTU is invalid.
Also, add a missing validation in read_buffer_size() and make it return
an error value if the validation fails.
Now hci_conn_add() returns ERR_PTR() as it can fail due to the both a
kzalloc failure and invalid MTU value.

divide error: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 0 PID: 67 Comm: kworker/u5:0 Tainted: G W 6.9.0-rc5+ #20
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
Workqueue: hci0 hci_rx_work
RIP: 0010:l2cap_le_flowctl_init+0x19e/0x3f0 net/bluetooth/l2cap_core.c:547
Code: e8 17 17 0c 00 66 41 89 9f 84 00 00 00 bf 01 00 00 00 41 b8 02 00 00 00 4c
89 fe 4c 89 e2 89 d9 e8 27 17 0c 00 44 89 f0 31 d2 <66> f7 f3 89 c3 ff c3 4d 8d
b7 88 00 00 00 4c 89 f0 48 c1 e8 03 42
RSP: 0018:ffff88810bc0f858 EFLAGS: 00010246
RAX: 00000000000002a0 RBX: 0000000000000000 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: ffff88810bc0f7c0 RDI: ffffc90002dcb66f
RBP: ffff88810bc0f880 R08: aa69db2dda70ff01 R09: 0000ffaaaaaaaaaa
R10: 0084000000ffaaaa R11: 0000000000000000 R12: ffff88810d65a084
R13: dffffc0000000000 R14: 00000000000002a0 R15: ffff88810d65a000
FS: 0000000000000000(0000) GS:ffff88811ac00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000100 CR3: 0000000103268003 CR4: 0000000000770ef0
PKRU: 55555554
Call Trace:
<TASK>
l2cap_le_connect_req net/bluetooth/l2cap_core.c:4902 [inline]
l2cap_le_sig_cmd net/bluetooth/l2cap_core.c:5420 [inline]
l2cap_le_sig_channel net/bluetooth/l2cap_core.c:5486 [inline]
l2cap_recv_frame+0xe59d/0x11710 net/bluetooth/l2cap_core.c:6809
l2cap_recv_acldata+0x544/0x10a0 net/bluetooth/l2cap_core.c:7506
hci_acldata_packet net/bluetooth/hci_core.c:3939 [inline]
hci_rx_work+0x5e5/0xb20 net/bluetooth/hci_core.c:4176
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0x90f/0x1530 kernel/workqueue.c:3335
worker_thread+0x926/0xe70 kernel/workqueue.c:3416
kthread+0x2e3/0x380 kernel/kthread.c:388
ret_from_fork+0x5c/0x90 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: Bluetooth: L2CAP: corrige div-by-zero en l2cap_le_flowctl_init() l2cap_le_flowctl_init() puede causar tanto div-by-zero como un desbordamiento de enteros ya que hdev->le_mtu puede no caer el rango válido. Mueva MTU de hci_dev a hci_conn para validar MTU y detener el proceso de conexión antes si MTU no es válido. Además, agregue una validación faltante en read_buffer_size() y haga que devuelva un valor de error si la validación falla. Ahora hci_conn_add() devuelve ERR_PTR() ya que puede fallar debido a una falla de kzalloc y un valor de MTU no válido. error de división: 0000 [#1] PREEMPT SMP KASAN NOPTI CPU: 0 PID: 67 Comm: kworker/u5:0 Tainted: GW 6.9.0-rc5+ #20 Nombre de hardware: PC estándar QEMU (i440FX + PIIX, 1996), BIOS 1.15.0-1 01/04/2014 Cola de trabajo: hci0 hci_rx_work RIP: 0010:l2cap_le_flowctl_init+0x19e/0x3f0 net/bluetooth/l2cap_core.c:547 Código: e8 17 17 0c 00 66 41 89 9f 84 00 00 novio 01 00 00 00 41 b8 02 00 00 00 4c 89 fe 4c 89 e2 89 d9 e8 27 17 0c 00 44 89 f0 31 d2 <66> f7 f3 89 c3 ff c3 4d 8d b7 88 00 00 00 4c 89 f0 48 c1 e8 03 42 RSP: 0018:ffff88810bc0f858 EFLAGS: 00010246 RAX: 00000000000002a0 RBX: 0000000000000000 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 810bc0f7c0 RDI: ffffc90002dcb66f RBP: ffff88810bc0f880 R08: aa69db2dda70ff01 R09: 0000ffaaaaaaaaaa R10: 0084000000ffaaaa R11: 0000000000000000 R12 : ffff88810d65a084 R13: dffffc0000000000 R14: 00000000000002a0 R15: ffff88810d65a000 FS: 0000000000000000(0000) GS:ffff88811ac00000(0000) knlGS:00000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 50033 CR2: 0000000020000100 CR3: 0000000103268003 CR4: 0000000000770ef0 PKRU: 55555554 Seguimiento de llamadas: l2cap_le_connect_req net /bluetooth/l2cap_core.c:4902 [en línea] l2cap_le_sig_cmd net/bluetooth/l2cap_core.c:5420 [en línea] l2cap_le_sig_channel net/bluetooth/l2cap_core.c:5486 [en línea] l2cap_recv_frame+0xe59d/0x11710 net/bluetooth/l2cap_core.c: 6809 l2cap_recv_acldata+0x544/0x10a0 net/bluetooth/l2cap_core.c:7506 hci_acldata_packet net/bluetooth/hci_core.c:3939 [en línea] hci_rx_work+0x5e5/0xb20 net/bluetooth/hci_core.c:4176 Process_one_work kernel/workqueue.c: 3254 [en línea] Process_scheduled_works+0x90f/0x1530 kernel/workqueue.c:3335 trabajador_thread+0x926/0xe70 kernel/workqueue.c:3416 kthread+0x2e3/0x380 kernel/kthread.c:388 ret_from_fork+0x5c/0x90 arch/x86/kernel/ Process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Módulos vinculados en: ---[ end trace 0000000000000000 ]---

*Credits: N/A

CVSS Scores

NISTv3.1 6.5

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Changed

Confidentiality

None

Integrity

None

Availability

High

* Common Vulnerability Scoring System

SSVC

Decision:Track

Exploitation

None

Automatable

Tech. Impact

Partial

* Organization's Worst-case Scenario

Timeline

2024-05-30 CVE Reserved
2024-06-08 CVE Published
2024-07-18 EPSS Updated
2024-11-05 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-190: Integer Overflow or Wraparound
CWE-369: Divide By Zero

CAPEC

References (6)

URL	Tag	Source
https://git.kernel.org/stable/c/6ed58ec520ad2b2fe3f955c8a5fd0eecafccebdf	Vuln. Introduced

URL	Date	SRC

URL	Date	SRC
https://git.kernel.org/stable/c/ad3f7986c5a0f82b8b66a0afe1cc1f5421e1d674	2024-05-25
https://git.kernel.org/stable/c/dfece2b4e3759759b2bdfac2cd6d0ee9fbf055f3	2024-05-25
https://git.kernel.org/stable/c/d2b2f7d3936dc5990549bc36ab7ac7ac37f22c30	2024-05-25
https://git.kernel.org/stable/c/4d3dbaa252257d20611c3647290e6171f1bbd6c8	2024-06-12
https://git.kernel.org/stable/c/a5b862c6a221459d54e494e88965b48dcfa6cc44	2024-05-14

URL	Date	SRC

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 2.6.39 < 6.6.32 Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.39 < 6.6.32"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 2.6.39 < 6.8.11 Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.39 < 6.8.11"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 2.6.39 < 6.9.2 Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.39 < 6.9.2"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 2.6.39 < 6.9.4 Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.39 < 6.9.4"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 2.6.39 < 6.10 Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.39 < 6.10"		en		Affected