// For flags

CVE-2024-35894

mptcp: prevent BPF accessing lowat from a subflow socket.

Severity Score

5.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

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

mptcp: prevent BPF accessing lowat from a subflow socket.

Alexei reported the following splat:

WARNING: CPU: 32 PID: 3276 at net/mptcp/subflow.c:1430 subflow_data_ready+0x147/0x1c0
Modules linked in: dummy bpf_testmod(O) [last unloaded: bpf_test_no_cfi(O)]
CPU: 32 PID: 3276 Comm: test_progs Tainted: GO 6.8.0-12873-g2c43c33bfd23
Call Trace:
<TASK>
mptcp_set_rcvlowat+0x79/0x1d0
sk_setsockopt+0x6c0/0x1540
__bpf_setsockopt+0x6f/0x90
bpf_sock_ops_setsockopt+0x3c/0x90
bpf_prog_509ce5db2c7f9981_bpf_test_sockopt_int+0xb4/0x11b
bpf_prog_dce07e362d941d2b_bpf_test_socket_sockopt+0x12b/0x132
bpf_prog_348c9b5faaf10092_skops_sockopt+0x954/0xe86
__cgroup_bpf_run_filter_sock_ops+0xbc/0x250
tcp_connect+0x879/0x1160
tcp_v6_connect+0x50c/0x870
mptcp_connect+0x129/0x280
__inet_stream_connect+0xce/0x370
inet_stream_connect+0x36/0x50
bpf_trampoline_6442491565+0x49/0xef
inet_stream_connect+0x5/0x50
__sys_connect+0x63/0x90
__x64_sys_connect+0x14/0x20

The root cause of the issue is that bpf allows accessing mptcp-level
proto_ops from a tcp subflow scope.

Fix the issue detecting the problematic call and preventing any action.

En el kernel de Linux se ha resuelto la siguiente vulnerabilidad: mptcp: impide que BPF acceda a lowat desde un socket de subflujo. Alexei informó el siguiente símbolo: ADVERTENCIA: CPU: 32 PID: 3276 en net/mptcp/subflow.c:1430 subflow_data_ready+0x147/0x1c0 Módulos vinculados en: ficticio bpf_testmod(O) [última descarga: bpf_test_no_cfi(O)] CPU: 32 PID: 3276 Comunicaciones: test_progs Contaminado: GO 6.8.0-12873-g2c43c33bfd23 Seguimiento de llamadas: mptcp_set_rcvlowat+0x79/0x1d0 sk_setsockopt+0x6c0/0x1540 __bpf_setsockopt+0x6f/0x90 ock_ops_setsockopt+0x3c/0x90 bpf_prog_509ce5db2c7f9981_bpf_test_sockopt_int+0xb4/0x11b bpf_prog_dce07e362d941d2b_bpf_test_socket_sockopt+0x12b /0x132 bpf_prog_348c9b5faaf10092_skops_sockopt+0x954/0xe86 __cgroup_bpf_run_filter_sock_ops+0xbc/0x250 tcp_connect+0x879/0x1160 tcp_v6_connect+0x50c/0x870 x129/0x280 __inet_stream_connect+0xce/0x370 inet_stream_connect+0x36/0x50 bpf_trampoline_6442491565+0x49/0xef inet_stream_connect+0x5/0x50 __sys_connect+0x63 /0x90 __x64_sys_connect+0x14/0x20 La causa principal del problema es que bpf permite acceder a proto_ops de nivel mptcp desde un alcance de subflujo tcp. Solucione el problema al detectar la llamada problemática y evitar cualquier acción.

*Credits: N/A
CVSS Scores
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2024-05-17 CVE Reserved
  • 2024-05-19 CVE Published
  • 2024-08-13 EPSS Updated
  • 2024-12-19 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
CAPEC
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"
 >= 6.7 < 6.8.5
Search vendor "Linux" for product "Linux Kernel" and version " >= 6.7 < 6.8.5"
en
Affected
Linux
Search vendor "Linux"
 Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
 >= 6.7 < 6.9
Search vendor "Linux" for product "Linux Kernel" and version " >= 6.7 < 6.9"
en
Affected