CVE-2025-21854

In the Linux kernel, the following vulnerability has been resolved: sockmap, vsock: For connectible sockets allow only connected sockmap expects all vsocks to have a transport assigned, which is expressed in vsock_proto::psock_update_sk_prot(). However, there is an edge case where an unconnected (connectible) socket may lose its previously assigned transport. This is handled with a NULL check in the vsock/BPF recv path. Another design detail is that listening vsocks are not supposed to have any transport assigned at all. Which implies they are not supported by the sockmap. But this is complicated by the fact that a socket, before switching to TCP_LISTEN, may have had some transport assigned during a failed connect() attempt. Hence, we may end up with a listening vsock in a sockmap, which blows up quickly: KASAN: null-ptr-deref in range [0x0000000000000120-0x0000000000000127] CPU: 7 UID: 0 PID: 56 Comm: kworker/7:0 Not tainted 6.14.0-rc1+ Workqueue: vsock-loopback vsock_loopback_work RIP: 0010:vsock_read_skb+0x4b/0x90 Call Trace: sk_psock_verdict_data_ready+0xa4/0x2e0 virtio_transport_recv_pkt+0x1ca8/0x2acc vsock_loopback_work+0x27d/0x3f0 process_one_work+0x846/0x1420 worker_thread+0x5b3/0xf80 kthread+0x35a/0x700 ret_from_fork+0x2d/0x70 ret_from_fork_asm+0x1a/0x30 For connectible sockets, instead of relying solely on the state of vsk->transport, tell sockmap to only allow those representing established connections. This aligns with the behaviour for AF_INET and AF_UNIX.
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:6.14:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:*

History

13 Mar 2025, 21:18

Type Values Removed Values Added
First Time Linux linux Kernel
Linux
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 5.5
CPE cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Summary
  • (es) En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: sockmap, vsock: Para sockets conectables, solo se permite que estén conectados. Sockmap espera que todos los vsocks tengan un transporte asignado, lo cual se expresa en vsock_proto::psock_update_sk_prot(). Sin embargo, existe un caso extremo en el que un socket no conectado (conectable) puede perder su transporte previamente asignado. Esto se gestiona con una comprobación de NULL en la ruta de recepción vsock/BPF. Otro detalle de diseño es que los vsocks que escuchan no deben tener ningún transporte asignado. Esto implica que no son compatibles con sockmap. Sin embargo, esto se complica por el hecho de que un socket, antes de cambiar a TCP_LISTEN, puede haber tenido algún transporte asignado durante un intento fallido de connect(). Por lo tanto, podemos terminar con un vsock escuchando en un sockmap, que explota rápidamente: KASAN: null-ptr-deref en el rango [0x0000000000000120-0x0000000000000127] CPU: 7 UID: 0 PID: 56 Comm: kworker/7:0 No contaminado 6.14.0-rc1+ Cola de trabajo: vsock-loopback vsock_loopback_work RIP: 0010:vsock_read_skb+0x4b/0x90 Rastreo de llamadas: sk_psock_verdict_data_ready+0xa4/0x2e0 virtio_transport_recv_pkt+0x1ca8/0x2acc vsock_loopback_work+0x27d/0x3f0 Para los sockets conectables, en lugar de depender únicamente del estado de vsk->transport, indique a sockmap que solo permita los que representan conexiones establecidas. Esto coincide con el comportamiento de AF_INET y AF_UNIX.
CWE CWE-476
References () https://git.kernel.org/stable/c/22b683217ad2112791a708693cb236507abd637a - () https://git.kernel.org/stable/c/22b683217ad2112791a708693cb236507abd637a - Patch
References () https://git.kernel.org/stable/c/8fb5bb169d17cdd12c2dcc2e96830ed487d77a0f - () https://git.kernel.org/stable/c/8fb5bb169d17cdd12c2dcc2e96830ed487d77a0f - Patch
References () https://git.kernel.org/stable/c/cc9a7832ede53ade1ba9991f0e27314caa4029d8 - () https://git.kernel.org/stable/c/cc9a7832ede53ade1ba9991f0e27314caa4029d8 - Patch
References () https://git.kernel.org/stable/c/f7b473e35986835cc2813fef7b9d40336a09247e - () https://git.kernel.org/stable/c/f7b473e35986835cc2813fef7b9d40336a09247e - Patch

12 Mar 2025, 10:15

Type Values Removed Values Added
New CVE

Information

Published : 2025-03-12 10:15

Updated : 2025-03-13 21:18


NVD link : CVE-2025-21854

Mitre link : CVE-2025-21854

CVE.ORG link : CVE-2025-21854


JSON object : View

Products Affected

linux

  • linux_kernel
CWE
CWE-476

NULL Pointer Dereference