smb: client: use kzalloc to zero-initialize security descriptor buffer
Summary
| CVE | CVE-2026-46139 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-05-28 10:16:29 UTC |
| Updated | 2026-05-28 13:44:01 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved: smb: client: use kzalloc to zero-initialize security descriptor buffer Commit 62e7dd0a39c2d ("smb: common: change the data type of num_aces to le16") split struct smb_acl's __le32 num_aces field into __le16 num_aces and __le16 reserved. The reserved field corresponds to Sbz2 in the MS-DTYP ACL wire format, which must be zero [1]. When building an ACL descriptor in build_sec_desc(), we are using a kmalloc()'ed descriptor buffer and writing the fields explicitly using le16() writes now. This never writes to the 2 byte reserved field, leaving it as uninitialized heap data. When the reserved field happens to contain non-zero slab garbage, Samba rejects the security descriptor with "ndr_pull_security_descriptor failed: Range Error", causing chmod to fail with EINVAL. Change kmalloc() to kzalloc() to ensure the entire buffer is zero-initialized. [1] https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-dtyp/20233ed8-a6c6-4097-aafa-dd545ed24428 |
Risk And Classification
EPSS: 0.000180000 probability, percentile 0.050770000 (date 2026-06-01)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 1593ddb37bd124c131fe635397df68e854a03108 4c3ed344a970aad51388ac3b0145b98318f0e21f git | Not specified |
| CNA | Linux | Linux | affected da087905e3270e2291c0afae39a28e7d183e5ec3 941a1e6eb35440336913afc88a82103291956d5d git | Not specified |
| CNA | Linux | Linux | affected 62e7dd0a39c2d0d7ff03274c36df971f1b3d2d0d be1ef9512a3f5a755895c24f31b334342f4aa15b git | Not specified |
| CNA | Linux | Linux | affected 62e7dd0a39c2d0d7ff03274c36df971f1b3d2d0d 9bdb2ca31368b7671949dfb94a5d57ffccd01edd git | Not specified |
| CNA | Linux | Linux | affected 62e7dd0a39c2d0d7ff03274c36df971f1b3d2d0d 5e489c6c47a2ac15edbaca153b9348e42c1eacab git | Not specified |
| CNA | Linux | Linux | affected 191f2f444745087c3c51fd6042a0e25f42315ab0 git | Not specified |
| CNA | Linux | Linux | affected 6.12.23 6.12.88 semver | Not specified |
| CNA | Linux | Linux | affected 6.13.11 6.14 semver | Not specified |
| CNA | Linux | Linux | affected 6.14 | Not specified |
| CNA | Linux | Linux | unaffected 6.14 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.88 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.30 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.0.7 7.0.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.1-rc3 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/941a1e6eb35440336913afc88a82103291956d5d | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/be1ef9512a3f5a755895c24f31b334342f4aa15b | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/9bdb2ca31368b7671949dfb94a5d57ffccd01edd | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/5e489c6c47a2ac15edbaca153b9348e42c1eacab | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/4c3ed344a970aad51388ac3b0145b98318f0e21f | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.