HighFix available
crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg
Type: advisorySources: OSV
In the Linux kernel, the following vulnerability has been resolved: crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg Issuing two writes to the same af_alg socket is bogus as the data will be interleaved in an unpredictable fashion. Furthermore, concurrent writes may create inconsistencies in the internal socket state. Disallow this by adding a new ctx->write field that indiciates exclusive ownership for writing.
- Products
- Kernel
- Affected versions
- Not specified
- Fixed versions
- 5.10.245, 5.15.194, 6.1.154, 6.12.49, 6.16.9, 6.6.108
- CVEs
- CVE-2025-39964
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 3 Nov 2026, 17:23 UTC · Revision 1
Source evidence
crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg
core-osv · Original sourcePublished 13 Oct 2025, 13:48 UTC
In the Linux kernel, the following vulnerability has been resolved: crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg Issuing two writes to the same af_alg socket is bogus as the data will be interleaved in an unpredictable fashion. Furthermore, concurrent writes may create inconsistencies in the internal socket state. Disallow this by adding a new ctx->write field that indiciates exclusive ownership for writing.
osv:CVE-2025-39964
Kernel
Fixed versions: 5.10.245, 5.15.194, 6.1.154, 6.6.108, 6.12.49, 6.16.9
Complete source record
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"title": "crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg",
"summary": "In the Linux kernel, the following vulnerability has been resolved: crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg Issuing two writes to the same af_alg socket is bogus as the data will be interleaved in an unpredictable fashion. Furthermore, concurrent writes may create inconsistencies in the internal socket state. Disallow this by adding a new ctx->write field that indiciates exclusive ownership for writing.",
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"modified": "2026-10-28T02:30:30.630733932Z",
"provider": "osv",
"references": [
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"https://cert-portal.siemens.com/productcert/html/ssa-457936.html",
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"https://nvd.nist.gov/vuln/detail/CVE-2025-39964",
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"provider_metadata": {
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"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/39xxx/CVE-2025-39964.json"
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"security_relevant": true,
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"source_id": "core-osv",
"document_id": 497778,
"published_at": "2025-10-13T13:48:30.334+00:00"
}