In the Linux kernel, the following vulnerability has been resolved: NFSD: Hold net reference for the lifetime of /proc/fs/nfs/exports fd The /proc/fs/nfs/exports proc entry is created at module init and persists for the module's lifetime. exports_proc_open() captures the caller's current network namespace and stores its svc_export_cache in seq->private, but takes no reference on the namespace. If the namespace is subsequently torn down (e.g. container destruction after the opener does setns() to a different namespace), nfsd_net_exit() calls nfsd_export_shutdown() which frees the cache. Subsequent reads on the still-open fd dereference the freed cache_detail, walking a freed hash table. Hold a reference on the struct net for the lifetime of the open file descriptor. This prevents nfsd_net_exit() from running -- and thus prevents nfsd_export_shutdown() from freeing the cache -- while any exports fd is open. cache_detail already stores its net pointer (cd->net, set by cache_create_net()), so exports_release() can retrieve it without additional per-file storage.
En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta: NFSD: Mantener la referencia de red durante la vida útil del fd /proc/fs/nfs/exports La entrada proc /proc/fs/nfs/exports se crea en la inicialización del módulo y persiste durante la vida útil del módulo. exports_proc_open() captura el espacio de nombres de red actual del llamador y almacena su svc_export_cache en seq -> private, pero no toma ninguna referencia sobre el espacio de nombres. Si el espacio de nombres se desmantela posteriormente (p. ej., destrucción del contenedor después de que el abridor haga setns() a un espacio de nombres diferente), nfsd_net_exit() llama a nfsd_export_shutdown() que libera la caché. Lecturas posteriores en el fd aún abierto desreferencian el cache_detail liberado, recorriendo una tabla hash liberada. Mantener una referencia sobre la struct net durante la vida útil del descriptor de archivo abierto. Esto evita que nfsd_net_exit() se ejecute -- y por lo tanto evita que nfsd_export_shutdown() libere la caché -- mientras cualquier fd de exportaciones esté abierto. cache_detail ya almacena su puntero de red (cd -> net, establecido por cache_create_net()), por lo que exports_release() puede recuperarlo sin almacenamiento adicional por archivo.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
| Attack Vector | LOCAL |
|---|---|
| Attack Complexity | LOW |
| Privileges Required | LOW |
| User Interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality Impact | HIGH |
| Integrity Impact | HIGH |
| Availability Impact | HIGH |
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Type: Secondary
Exploitability Score: 1.8
Impact Score: 5.9
| Source | Type | Description |
|---|---|---|
| [email protected] | Primary |
en
NVD-CWE-noinfo
|
| Vendor | Product | Version | Update | Type |
|---|---|---|---|---|
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d2357b4dd80> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d242a707a00> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d2364a4c940> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d2424785a40> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d2357b4f900> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d23bea64200> | Operating System |
| linux | linux_kernel | 7.0 | <built-in method update of dict object at 0x7d2364a4e5c0> | Operating System |
| linux | linux_kernel | 7.0 | <built-in method update of dict object at 0x7d2364a4d7c0> | Operating System |
| linux | linux_kernel | 7.0 | <built-in method update of dict object at 0x7d2364a4ca80> | Operating System |
| linux | linux_kernel | 7.0 | <built-in method update of dict object at 0x7d2357b4cb80> | Operating System |
| Vulnerable | CPE |
|---|---|
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:* |