CVE-2026-23304

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2026-23304
In the Linux kernel, the following vulnerability has been resolved: ipv6: fix NULL pointer deref in ip6_rt_get_dev_rcu() l3mdev_master_dev_rcu() can return NULL when the slave device is being un-slaved from a VRF. All other callers deal with this, but we lost the fallback to loopback in ip6_rt_pcpu_alloc() -> ip6_rt_get_dev_rcu() with commit 4832c30d5458 ("net: ipv6: put host and anycast routes on device with address"). KASAN: null-ptr-deref in range [0x0000000000000108-0x000000000000010f] RIP: 0010:ip6_rt_pcpu_alloc (net/ipv6/route.c:1418) Call Trace: ip6_pol_route (net/ipv6/route.c:2318) fib6_rule_lookup (net/ipv6/fib6_rules.c:115) ip6_route_output_flags (net/ipv6/route.c:2607) vrf_process_v6_outbound (drivers/net/vrf.c:437) I was tempted to rework the un-slaving code to clear the flag first and insert synchronize_rcu() before we remove the upper. But looks like the explicit fallback to loopback_dev is an established pattern. And I guess avoiding the synchronize_rcu() is nice, too.

5.5 /10

CVSS v3 : MEDIUM

V3 Legend

Vector :

Exploitability : 1.8 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://git.kernel.org/stable/c/0b5a7826020706057cc5a9d9009e667027f221ee Patch
https://git.kernel.org/stable/c/2ffb4f5c2ccb2fa1c049dd11899aee7967deef5a Patch
https://git.kernel.org/stable/c/3310fc11fc47387d1dd4759b0bc961643ea11c7f Patch
https://git.kernel.org/stable/c/4a48fe59f29f673a3d042d679f26629a9c3e29d4 Patch
https://git.kernel.org/stable/c/581800298313c9fd75e94985e6d37d21b7e35d34 Patch
https://git.kernel.org/stable/c/a73fe9f4ae84a239d5b2686f47a58c158aee2eb4 Patch
https://git.kernel.org/stable/c/ae88c8256547b63980770a9ea7be73a15900d27e Patch
https://git.kernel.org/stable/c/d542e2ac7f9e288d49735be0775611547ca4e0ee Patch
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*
History

28 May 2026, 14:34

Type Values Removed Values Added
CWE CWE-476
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 5.5
First Time Linux
Linux linux Kernel
CPE cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*
References () https://git.kernel.org/stable/c/0b5a7826020706057cc5a9d9009e667027f221ee - () https://git.kernel.org/stable/c/0b5a7826020706057cc5a9d9009e667027f221ee - Patch
References () https://git.kernel.org/stable/c/2ffb4f5c2ccb2fa1c049dd11899aee7967deef5a - () https://git.kernel.org/stable/c/2ffb4f5c2ccb2fa1c049dd11899aee7967deef5a - Patch
References () https://git.kernel.org/stable/c/3310fc11fc47387d1dd4759b0bc961643ea11c7f - () https://git.kernel.org/stable/c/3310fc11fc47387d1dd4759b0bc961643ea11c7f - Patch
References () https://git.kernel.org/stable/c/4a48fe59f29f673a3d042d679f26629a9c3e29d4 - () https://git.kernel.org/stable/c/4a48fe59f29f673a3d042d679f26629a9c3e29d4 - Patch
References () https://git.kernel.org/stable/c/581800298313c9fd75e94985e6d37d21b7e35d34 - () https://git.kernel.org/stable/c/581800298313c9fd75e94985e6d37d21b7e35d34 - Patch
References () https://git.kernel.org/stable/c/a73fe9f4ae84a239d5b2686f47a58c158aee2eb4 - () https://git.kernel.org/stable/c/a73fe9f4ae84a239d5b2686f47a58c158aee2eb4 - Patch
References () https://git.kernel.org/stable/c/ae88c8256547b63980770a9ea7be73a15900d27e - () https://git.kernel.org/stable/c/ae88c8256547b63980770a9ea7be73a15900d27e - Patch
References () https://git.kernel.org/stable/c/d542e2ac7f9e288d49735be0775611547ca4e0ee - () https://git.kernel.org/stable/c/d542e2ac7f9e288d49735be0775611547ca4e0ee - Patch

18 Apr 2026, 09:16

Type Values Removed Values Added
Summary
  • (es) En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta: ipv6: corrección de desreferencia de puntero NULL en ip6_rt_get_dev_rcu() l3mdev_master_dev_rcu() puede devolver NULL cuando el dispositivo esclavo está siendo desasociado de un VRF. Todos los demás llamadores manejan esto, pero perdimos la alternativa a loopback en ip6_rt_pcpu_alloc() -> ip6_rt_get_dev_rcu() con el commit 4832c30d5458 ('net: ipv6: put host and anycast routes on device with address'). KASAN: desreferencia de puntero nulo en el rango [0x0000000000000108-0x000000000000010f] RIP: 0010:ip6_rt_pcpu_alloc (net/ipv6/route.c:1418) Traza de Llamadas: ip6_pol_route (net/ipv6/route.c:2318) fib6_rule_lookup (net/ipv6/fib6_rules.c:115) ip6_route_output_flags (net/ipv6/route.c:2607) vrf_process_v6_outbound (drivers/net/vrf.c:437) Me sentí tentado a reelaborar el código de desasociación para borrar la bandera primero e insertar synchronize_rcu() antes de que eliminemos el superior. Pero parece que la alternativa explícita a loopback_dev es un patrón establecido. Y supongo que evitar el synchronize_rcu() también es bueno.
References
  • () https://git.kernel.org/stable/c/a73fe9f4ae84a239d5b2686f47a58c158aee2eb4 -
  • () https://git.kernel.org/stable/c/d542e2ac7f9e288d49735be0775611547ca4e0ee -

25 Mar 2026, 11:16

Type Values Removed Values Added
New CVE
Information

Published : 2026-03-25 11:16

Updated : 2026-05-28 14:34

NVD link : CVE-2026-23304

Mitre link : CVE-2026-23304

CVE.ORG link : CVE-2026-23304

JSON object : View

Products Affected

linux

  • linux_kernel
CWE
CWE-476

NULL Pointer Dereference