CVE-2021-47309

net: validate lwtstate->data before returning from skb_tunnel_info()

Severity Score

"-"

*CVSS v-

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:

net: validate lwtstate->data before returning from skb_tunnel_info()

skb_tunnel_info() returns pointer of lwtstate->data as ip_tunnel_info
type without validation. lwtstate->data can have various types such as
mpls_iptunnel_encap, etc and these are not compatible.
So skb_tunnel_info() should validate before returning that pointer.

Splat looks like:
BUG: KASAN: slab-out-of-bounds in vxlan_get_route+0x418/0x4b0 [vxlan]
Read of size 2 at addr ffff888106ec2698 by task ping/811

CPU: 1 PID: 811 Comm: ping Not tainted 5.13.0+ #1195
Call Trace:
dump_stack_lvl+0x56/0x7b
print_address_description.constprop.8.cold.13+0x13/0x2ee
? vxlan_get_route+0x418/0x4b0 [vxlan]
? vxlan_get_route+0x418/0x4b0 [vxlan]
kasan_report.cold.14+0x83/0xdf
? vxlan_get_route+0x418/0x4b0 [vxlan]
vxlan_get_route+0x418/0x4b0 [vxlan]
[ ... ]
vxlan_xmit_one+0x148b/0x32b0 [vxlan]
[ ... ]
vxlan_xmit+0x25c5/0x4780 [vxlan]
[ ... ]
dev_hard_start_xmit+0x1ae/0x6e0
__dev_queue_xmit+0x1f39/0x31a0
[ ... ]
neigh_xmit+0x2f9/0x940
mpls_xmit+0x911/0x1600 [mpls_iptunnel]
lwtunnel_xmit+0x18f/0x450
ip_finish_output2+0x867/0x2040
[ ... ]

En el kernel de Linux, se resolvió la siguiente vulnerabilidad: net: validar lwtstate->data antes de regresar de skb_tunnel_info() skb_tunnel_info() devuelve un puntero de lwtstate->data como tipo ip_tunnel_info sin validación. lwtstate->data puede tener varios tipos como mpls_iptunnel_encap, etc. y estos no son compatibles. Entonces skb_tunnel_info() debería validarse antes de devolver ese puntero. Splat se ve así: BUG: KASAN: slab fuera de los límites en vxlan_get_route+0x418/0x4b0 [vxlan] Lectura de tamaño 2 en la dirección ffff888106ec2698 mediante tarea ping/811 CPU: 1 PID: 811 Comm: ping No contaminado 5.13.0 + #1195 Seguimiento de llamadas: dump_stack_lvl+0x56/0x7b print_address_description.constprop.8.cold.13+0x13/0x2ee? vxlan_get_route+0x418/0x4b0 [vxlan] ? vxlan_get_route+0x418/0x4b0 [vxlan] kasan_report.cold.14+0x83/0xdf? vxlan_get_route+0x418/0x4b0 [vxlan] vxlan_get_route+0x418/0x4b0 [vxlan] [ ... ] vxlan_xmit_one+0x148b/0x32b0 [vxlan] [ ... ] vxlan_xmit+0x25c5/0x4780 [vxlan] [ ... ] +0x1ae /0x6e0 __dev_queue_xmit+0x1f39/0x31a0 [...] veck_xMit+0x2f9/0x940 mpls_xmit+0x911/0x1600 [mpls_iptunnel] lwtunnel_xmit+0x18f/0x450 ip_finish_output2+0x20467/0x2040

*Credits: N/A

CVSS Scores

Attack Vector

Attack Complexity

Privileges Required

User Interaction

Scope

Confidentiality

Integrity

Availability

* Common Vulnerability Scoring System

SSVC

Decision:Track

Exploitation

None

Automatable

Tech. Impact

Partial

* Organization's Worst-case Scenario

Timeline

2024-05-21 CVE Reserved
2024-05-21 CVE Published
2024-05-22 EPSS Updated
2024-08-04 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CAPEC

References (9)

URL	Tag	Source
https://git.kernel.org/stable/c/61adedf3e3f1d3f032c5a6a299978d91eff6d555	Vuln. Introduced

URL	Date	SRC

URL	Date	SRC
https://git.kernel.org/stable/c/e7f3c9df40515a6c6b46f36c4c94cf48a043f887	2021-07-28
https://git.kernel.org/stable/c/b61d327cd3cc5ea591f3bf751dd11e034f388bb5	2021-07-28
https://git.kernel.org/stable/c/83bdcfbd968bcc91a0632b7b625e4a9b0cba5e0d	2021-07-28
https://git.kernel.org/stable/c/8bb1589c89e61e3b182dd546f1021928ebb5c2a6	2021-07-28
https://git.kernel.org/stable/c/8aa13a86964cdec4fd969ef677c6614ff068641a	2021-07-25
https://git.kernel.org/stable/c/2179d96ec702cc33ead02a9ce40ece599b8538c5	2021-07-25
https://git.kernel.org/stable/c/a915379594f1e045421635c6316d8f3ffa018c58	2021-07-25
https://git.kernel.org/stable/c/67a9c94317402b826fc3db32afc8f39336803d97	2021-07-09

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"				>= 4.3 < 4.4.277 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.3 < 4.4.277"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.3 < 4.9.277 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.3 < 4.9.277"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.3 < 4.14.241 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.3 < 4.14.241"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.3 < 4.19.199 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.3 < 4.19.199"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.3 < 5.4.135 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.3 < 5.4.135"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.3 < 5.10.53 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.3 < 5.10.53"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.3 < 5.13.5 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.3 < 5.13.5"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.3 < 5.14 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.3 < 5.14"		en		Affected