CVE-2026-31403 in Kernel
Résumé (Anglaise)
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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Responsable
Linux
Réserver
09/03/2026
Divulgation
03/04/2026
Statut
Confirmé
Entrées
VulDB provides additional information and datapoints for this CVE:
| ID | Vulnérabilité | CWE | Exp | Con | CVE |
|---|---|---|---|---|---|
| 355172 | Linux Kernel NFSD exports exports_proc_open déni de service | 769 | Non défini | Correctif officiel | CVE-2026-31403 |