NFS/localio: fix ref leak on nfs_uuid_add_file failure
When nfs_uuid_add_file() races with nfs_uuid_put() tearing down
uuid->net, it returns -ENXIO without publishing nfl->nfs_uuid via
rcu_assign_pointer(). nfs_open_local_fh() then enters its error
branch and only releases the slot's file ref and its paired net
ref plus its own entry-time net ref, while the close path is a
no-op:
nfs_close_local_fh()
nfs_uuid = rcu_dereference(nfl->nfs_uuid);
if (!nfs_uuid) { rcu_read_unlock(); return; } /* always */
nfsd_open_local_fh() returns localio holding a caller-owned +1
nfsd_file reference (from nfsd_file_get() after
nfsd_file_acquire_local()) and an entry-time nfsd_net reference
(from its first nfsd_net_try_get()) embedded as nf->nf_net. Both
are leaked on the failure path, pinning one nfsd_file (and the
underlying struct file, dentry, inode) and one nfsd_net_ref per
occurrence, which blocks nfsd_net and netns teardown.
Fix by releasing the caller-owned file ref and its net ref through
the existing helper, using a stack-local RCU pointer so the helper
can xchg it out, then returning -ENXIO so callers do not
dereference a localio whose slot has been cleared:
struct nfsd_file __rcu *tmp = RCU_INITIALIZER(localio);
nfs_to_nfsd_file_put_local(pnf);
nfs_to_nfsd_file_put_local(&tmp);
localio = ERR_PTR(-ENXIO);
The trailing nfs_to_nfsd_net_put(net) continues to release the
outer net ref, so all three nfsd_net_try_get() increments are
balanced on the error branch.
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Sat, 12 Sep 2026 08:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-401 |
Fri, 11 Sep 2026 23:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: NFS/localio: fix ref leak on nfs_uuid_add_file failure When nfs_uuid_add_file() races with nfs_uuid_put() tearing down uuid->net, it returns -ENXIO without publishing nfl->nfs_uuid via rcu_assign_pointer(). nfs_open_local_fh() then enters its error branch and only releases the slot's file ref and its paired net ref plus its own entry-time net ref, while the close path is a no-op: nfs_close_local_fh() nfs_uuid = rcu_dereference(nfl->nfs_uuid); if (!nfs_uuid) { rcu_read_unlock(); return; } /* always */ nfsd_open_local_fh() returns localio holding a caller-owned +1 nfsd_file reference (from nfsd_file_get() after nfsd_file_acquire_local()) and an entry-time nfsd_net reference (from its first nfsd_net_try_get()) embedded as nf->nf_net. Both are leaked on the failure path, pinning one nfsd_file (and the underlying struct file, dentry, inode) and one nfsd_net_ref per occurrence, which blocks nfsd_net and netns teardown. Fix by releasing the caller-owned file ref and its net ref through the existing helper, using a stack-local RCU pointer so the helper can xchg it out, then returning -ENXIO so callers do not dereference a localio whose slot has been cleared: struct nfsd_file __rcu *tmp = RCU_INITIALIZER(localio); nfs_to_nfsd_file_put_local(pnf); nfs_to_nfsd_file_put_local(&tmp); localio = ERR_PTR(-ENXIO); The trailing nfs_to_nfsd_net_put(net) continues to release the outer net ref, so all three nfsd_net_try_get() increments are balanced on the error branch. | |
| Title | NFS/localio: fix ref leak on nfs_uuid_add_file failure | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-11T19:46:29.227Z
Reserved: 2026-09-11T19:38:34.751Z
Link: CVE-2026-89715
No data.
Status : Received
Published: 2026-09-11T20:19:58.993
Modified: 2026-09-11T20:19:58.993
Link: CVE-2026-89715
No data.
OpenCVE Enrichment
Updated: 2026-09-12T08:15:07Z
-
CWE-401
Missing Release of Memory after Effective Lifetime