In the Linux kernel, the following vulnerability has been resolved:
VFS: fix possible failure to unlock in nfsd4_create_file()
atomic_create() in fs/namei.c drops the reference to the dentry
when it returns an error.
This behaviour was imported into dentry_create() so that it
will drop the reference if an error is returned from atomic_create(),
though not if vfs_create() returns an error (in the case where
->atomic_create is not supported).
The caller - nfsd4_create_file() - is made aware of this by checking
path->dentry, which will either be a counted reference to a dentry, or
an error pointer.
However the change to use start_creating()/end_creating() (which landed
shortly before the dentry_create() change landed, though was likely
developed around the same time) means that nfsd4_create_file() *needs* a
valid dentry so that it can unlock the parent.
The net result is that if NFSD exports a filesystem which uses
->atomic_create, and if a call to ->atomic_create returns an error, then
nfsd4_create_file() will pass an error pointer to end_creating()
and the parent will not be unlocked.
Fix this by changing dentry_create() to make sure path->dentry is always
a valid dentry, never an error-pointer. The actual error is already
returned a different way.
Note that if ->atomic_create() returns a different dentry (which may not
be possible in practice) we are guaranteed (because it is only ever
provided by d_spliace_alias()) that it will have the same d_parent and
so it will have the same effect when passed to end_creating().
Metrics
Affected Vendors & Products
| Vendors | Products |
|---|---|
| Linux |
|
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References
History
Thu, 25 Jun 2026 09:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: VFS: fix possible failure to unlock in nfsd4_create_file() atomic_create() in fs/namei.c drops the reference to the dentry when it returns an error. This behaviour was imported into dentry_create() so that it will drop the reference if an error is returned from atomic_create(), though not if vfs_create() returns an error (in the case where ->atomic_create is not supported). The caller - nfsd4_create_file() - is made aware of this by checking path->dentry, which will either be a counted reference to a dentry, or an error pointer. However the change to use start_creating()/end_creating() (which landed shortly before the dentry_create() change landed, though was likely developed around the same time) means that nfsd4_create_file() *needs* a valid dentry so that it can unlock the parent. The net result is that if NFSD exports a filesystem which uses ->atomic_create, and if a call to ->atomic_create returns an error, then nfsd4_create_file() will pass an error pointer to end_creating() and the parent will not be unlocked. Fix this by changing dentry_create() to make sure path->dentry is always a valid dentry, never an error-pointer. The actual error is already returned a different way. Note that if ->atomic_create() returns a different dentry (which may not be possible in practice) we are guaranteed (because it is only ever provided by d_spliace_alias()) that it will have the same d_parent and so it will have the same effect when passed to end_creating(). | |
| Title | VFS: fix possible failure to unlock in nfsd4_create_file() | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-06-25T08:39:38.468Z
Reserved: 2026-06-09T07:44:35.393Z
Link: CVE-2026-53244
Vulnrichment
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NVD
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Redhat
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OpenCVE Enrichment
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