CVE-2026-53395

nfsd: fix dead ACL conflict guard in nfsd4_create

HIGH
7.5
CVSS Score
Published: July 19, 2026 at 12:01 PM UTC
Updated: August 17, 2026 at 05:17 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
HIGH7.5
Exploit prediction
EPSS 0.5%

Description

In the Linux kernel, the following vulnerability has been resolved: nfsd: fix dead ACL conflict guard in nfsd4_create nfsd4_create() steals create->cr_dpacl/cr_pacl into the local nfsd_attrs via the designated initializer, then immediately sets the source pointers to NULL. The subsequent conflict guard tests the already-nilled source fields, making it permanently dead code: if (create->cr_acl) { if (create->cr_dpacl || create->cr_pacl) /* always false */ When a client encodes both FATTR4_WORD0_ACL and FATTR4_WORD2_POSIX_{DEFAULT,ACCESS}_ACL in the same CREATE fattr bitmap, nfsd4_acl_to_attr() overwrites attrs.na_pacl/na_dpacl without releasing the originals, leaking two posix_acl slab objects per request. Repeated requests cause unbounded slab exhaustion. Fix by checking attrs.na_dpacl/na_pacl (the stolen values) instead of the nilled create->cr_dpacl/cr_pacl, matching the correct pattern already used in nfsd4_setattr().

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

7.0 ≤ v < 7.1.37.0 ≤ v < 7.27.0d2ca50606f5f0235d7780c1cd73b6614a5d07620
Vendor states this is fixed in 8371cc5c0a2cc2a71b3dcfd47ff1f7fcfc526a5e (fixed)
Vendor states this is fixed in a60f25a800846ab8e5a13f8a9d05111f2aee55a7 (fixed)
Vendor states this is fixed in 7.0 (unaffected)
Vendor states this is fixed in 7.1.3 (unaffected)
Vendor states this is fixed in 7.2 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

CVSS

7.5HIGHLinux
Vector?

Quick Info

StatusANALYZED
CWE
CWE-674

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