CVE-2025-21958

In the Linux kernel, the following vulnerability has been resolved: Revert "openvswitch: switch to per-action label counting in conntrack" Currently, ovs_ct_set_labels() is only called for confirmed conntrack entries (ct) within ovs_ct_commit(). However, if the conntrack entry does not have the labels_ext extension, attempting to allocate it in ovs_ct_get_conn_labels() for a confirmed entry triggers a warning in nf_ct_ext_add(): WARN_ON(nf_ct_is_confirmed(ct)); This happens when the conntrack entry is created externally before OVS increments net->ct.labels_used. The issue has become more likely since commit fcb1aa5163b1 ("openvswitch: switch to per-action label counting in conntrack"), which changed to use per-action label counting and increment net->ct.labels_used when a flow with ct action is added. Since there’s no straightforward way to fully resolve this issue at the moment, this reverts the commit to avoid breaking existing use cases.
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:6.14:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc6:*:*:*:*:*:*

History

31 Oct 2025, 19:44

Type Values Removed Values Added
Summary
  • (es) En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: Revertir "openvswitch: cambiar al conteo de etiquetas por acción en conntrack". Actualmente, ovs_ct_set_labels() solo se llama para entradas de conntrack confirmadas (ct) dentro de ovs_ct_commit(). Sin embargo, si la entrada de conntrack no tiene la extensión labels_ext, al intentar asignarla en ovs_ct_get_conn_labels() para una entrada confirmada, se genera una advertencia en nf_ct_ext_add(): WARN_ON(nf_ct_is_confirmed(ct)); Esto ocurre cuando la entrada de conntrack se crea externamente antes de que OVS incremente net->ct.labels_used. El problema se ha vuelto más frecuente desde el commit fcb1aa5163b1 ("openvswitch: cambio al conteo de etiquetas por acción en conntrack"), que cambió para usar el conteo de etiquetas por acción e incrementar net->ct.labels_used al agregar un flujo con la acción ct. Dado que actualmente no existe una solución directa para este problema, esta reversión de el commit evita la interrupción de los casos de uso existentes.
References () https://git.kernel.org/stable/c/1063ae07383c0ddc5bcce170260c143825846b03 - () https://git.kernel.org/stable/c/1063ae07383c0ddc5bcce170260c143825846b03 - Patch
References () https://git.kernel.org/stable/c/9e79fdabd52cfce1a021640a81256878a2c516a2 - () https://git.kernel.org/stable/c/9e79fdabd52cfce1a021640a81256878a2c516a2 - Patch
References () https://git.kernel.org/stable/c/d91bfc64a4886102746e74d2c6f3a61e9a77fd7d - () https://git.kernel.org/stable/c/d91bfc64a4886102746e74d2c6f3a61e9a77fd7d - Patch
CWE NVD-CWE-noinfo
CWE-367
CPE cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc6:*:*:*:*:*:*
First Time Linux linux Kernel
Linux
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 4.7

01 Apr 2025, 16:15

Type Values Removed Values Added
New CVE

Information

Published : 2025-04-01 16:15

Updated : 2025-10-31 19:44


NVD link : CVE-2025-21958

Mitre link : CVE-2025-21958

CVE.ORG link : CVE-2025-21958


JSON object : View

Products Affected

linux

  • linux_kernel
CWE
CWE-367

Time-of-check Time-of-use (TOCTOU) Race Condition

NVD-CWE-noinfo