CVE-2026-31403 in Kernel

Sumário (Inglês)

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.

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Responsável

Linux

Reservar

09/03/2026

Divulgação

03/04/2026

Estado

Confirmado

Inscrições

VulDB provides additional information and datapoints for this CVE:

ID	Vulnerabilidade	CWE	Exp	Con	CVE
355172	Linux Kernel NFSD exports exports_proc_open Negação de Serviço	769	Não definido	Correção oficial	CVE-2026-31403

Fontes

• MITRE
• NVD
• CVE Details