CVE-2024-35884

In the Linux kernel, the following vulnerability has been resolved: udp: do not accept non-tunnel GSO skbs landing in a tunnel When rx-udp-gro-forwarding is enabled UDP packets might be GROed when being forwarded. If such packets might land in a tunnel this can cause various issues and udp_gro_receive makes sure this isn't the case by looking for a matching socket. This is performed in udp4/6_gro_lookup_skb but only in the current netns. This is an issue with tunneled packets when the endpoint is in another netns. In such cases the packets will be GROed at the UDP level, which leads to various issues later on. The same thing can happen with rx-gro-list. We saw this with geneve packets being GROed at the UDP level. In such case gso_size is set; later the packet goes through the geneve rx path, the geneve header is pulled, the offset are adjusted and frag_list skbs are not adjusted with regard to geneve. When those skbs hit skb_fragment, it will misbehave. Different outcomes are possible depending on what the GROed skbs look like; from corrupted packets to kernel crashes. One example is a BUG_ON[1] triggered in skb_segment while processing the frag_list. Because gso_size is wrong (geneve header was pulled) skb_segment thinks there is "geneve header size" of data in frag_list, although it's in fact the next packet. The BUG_ON itself has nothing to do with the issue. This is only one of the potential issues. Looking up for a matching socket in udp_gro_receive is fragile: the lookup could be extended to all netns (not speaking about performances) but nothing prevents those packets from being modified in between and we could still not find a matching socket. It's OK to keep the current logic there as it should cover most cases but we also need to make sure we handle tunnel packets being GROed too early. This is done by extending the checks in udp_unexpected_gso: GSO packets lacking the SKB_GSO_UDP_TUNNEL/_CSUM bits and landing in a tunnel must be segmented. [1] kernel BUG at net/core/skbuff.c:4408! RIP: 0010:skb_segment+0xd2a/0xf70 __udp_gso_segment+0xaa/0x560
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:6.9:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.9:rc2:*:*:*:*:*:*

Configuration 2 (hide)

cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

History

23 Dec 2025, 19:28

Type Values Removed Values Added
CWE CWE-617
First Time Linux
Debian
Debian debian Linux
Linux linux Kernel
CVSS v2 : unknown
v3 : 8.8
v2 : unknown
v3 : 5.5
CPE cpe:2.3:o:linux:linux_kernel:6.9:rc2:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.9:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
References () https://git.kernel.org/stable/c/3001e7aa43d6691db2a878b0745b854bf12ddd19 - () https://git.kernel.org/stable/c/3001e7aa43d6691db2a878b0745b854bf12ddd19 - Patch
References () https://git.kernel.org/stable/c/3391b157780bbedf8ef9f202cbf10ee90bf6b0f8 - () https://git.kernel.org/stable/c/3391b157780bbedf8ef9f202cbf10ee90bf6b0f8 - Patch
References () https://git.kernel.org/stable/c/35fe0e0b5c00bef7dde74842a2564c43856fbce4 - () https://git.kernel.org/stable/c/35fe0e0b5c00bef7dde74842a2564c43856fbce4 - Patch
References () https://git.kernel.org/stable/c/3d010c8031e39f5fa1e8b13ada77e0321091011f - () https://git.kernel.org/stable/c/3d010c8031e39f5fa1e8b13ada77e0321091011f - Patch
References () https://git.kernel.org/stable/c/d12245080cb259d82b34699f6cd4ec11bdb688bd - () https://git.kernel.org/stable/c/d12245080cb259d82b34699f6cd4ec11bdb688bd - Patch
References () https://git.kernel.org/stable/c/d49ae15a5767d4e9ef8bbb79e42df1bfebc94670 - () https://git.kernel.org/stable/c/d49ae15a5767d4e9ef8bbb79e42df1bfebc94670 - Patch
References () https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html - () https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html - Third Party Advisory

21 Nov 2024, 09:21

Type Values Removed Values Added
References
  • () https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html -
References () https://git.kernel.org/stable/c/3001e7aa43d6691db2a878b0745b854bf12ddd19 - () https://git.kernel.org/stable/c/3001e7aa43d6691db2a878b0745b854bf12ddd19 -
References () https://git.kernel.org/stable/c/3391b157780bbedf8ef9f202cbf10ee90bf6b0f8 - () https://git.kernel.org/stable/c/3391b157780bbedf8ef9f202cbf10ee90bf6b0f8 -
References () https://git.kernel.org/stable/c/35fe0e0b5c00bef7dde74842a2564c43856fbce4 - () https://git.kernel.org/stable/c/35fe0e0b5c00bef7dde74842a2564c43856fbce4 -
References () https://git.kernel.org/stable/c/3d010c8031e39f5fa1e8b13ada77e0321091011f - () https://git.kernel.org/stable/c/3d010c8031e39f5fa1e8b13ada77e0321091011f -
References () https://git.kernel.org/stable/c/d12245080cb259d82b34699f6cd4ec11bdb688bd - () https://git.kernel.org/stable/c/d12245080cb259d82b34699f6cd4ec11bdb688bd -
References () https://git.kernel.org/stable/c/d49ae15a5767d4e9ef8bbb79e42df1bfebc94670 - () https://git.kernel.org/stable/c/d49ae15a5767d4e9ef8bbb79e42df1bfebc94670 -

13 Nov 2024, 19:35

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 8.8

05 Nov 2024, 10:16

Type Values Removed Values Added
References
  • {'url': 'https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html', 'source': '416baaa9-dc9f-4396-8d5f-8c081fb06d67'}

25 Jun 2024, 22:15

Type Values Removed Values Added
References
  • () https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html -
Summary
  • (es) En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: udp: no acepte skbs GSO que no sean de túnel que aterricen en un túnel Cuando rx-udp-gro-forwarding está habilitado, los paquetes UDP pueden recibir GRO al reenviarse. Si dichos paquetes pudieran aterrizar en un túnel, esto puede causar varios problemas y udp_gro_receive se asegura de que este no sea el caso buscando un socket coincidente. Esto se realiza en udp4/6_gro_lookup_skb pero sólo en las redes actuales. Este es un problema con los paquetes tunelizados cuando el punto final está en otra red. En tales casos, los paquetes se almacenarán en el nivel UDP, lo que generará varios problemas más adelante. Lo mismo puede pasar con rx-gro-list. Vimos esto con paquetes geneve siendo GRO en el nivel UDP. En tal caso, se establece gso_size; luego, el paquete pasa por la ruta geneve rx, se extrae el encabezado geneve, se ajusta el desplazamiento y los skbs frag_list no se ajustan con respecto a geneve. Cuando esos skbs lleguen a skb_fragment, se comportará mal. Son posibles diferentes resultados dependiendo del aspecto de los skbs GROed; desde paquetes corruptos hasta fallas del kernel. Un ejemplo es un BUG_ON[1] activado en skb_segment mientras se procesa frag_list. Debido a que gso_size es incorrecto (se extrajo el encabezado geneve), skb_segment cree que hay un "tamaño de encabezado geneve" de datos en frag_list, aunque en realidad es el siguiente paquete. El BUG_ON en sí no tiene nada que ver con el problema. Éste es sólo uno de los posibles problemas. Buscar un socket coincidente en udp_gro_receive es frágil: la búsqueda podría extenderse a todas las redes (sin hablar de rendimiento), pero nada impide que esos paquetes se modifiquen en el medio y todavía no pudimos encontrar un socket coincidente. Está bien mantener la lógica actual allí, ya que debería cubrir la mayoría de los casos, pero también debemos asegurarnos de manejar los paquetes de túnel que se procesan en GRO demasiado pronto. Esto se hace ampliando las comprobaciones en udp_unexpected_gso: los paquetes OSG que carecen de los bits SKB_GSO_UDP_TUNNEL/_CSUM y que aterrizan en un túnel deben segmentarse. [1] ¡BUG del kernel en net/core/skbuff.c:4408! RIP: 0010:skb_segment+0xd2a/0xf70 __udp_gso_segment+0xaa/0x560

19 May 2024, 09:15

Type Values Removed Values Added
New CVE

Information

Published : 2024-05-19 09:15

Updated : 2025-12-23 19:28


NVD link : CVE-2024-35884

Mitre link : CVE-2024-35884

CVE.ORG link : CVE-2024-35884


JSON object : View

Products Affected

debian

  • debian_linux

linux

  • linux_kernel
CWE
CWE-617

Reachable Assertion