CVE-2025-39682

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Source
https://cve.org/CVERecord?id=CVE-2025-39682
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-39682.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2025-39682
Downstream
Related
Published
2025-09-05T17:20:48.657Z
Modified
2026-03-20T12:43:00.525779Z
Summary
tls: fix handling of zero-length records on the rx_list
Details

In the Linux kernel, the following vulnerability has been resolved:

tls: fix handling of zero-length records on the rx_list

Each recvmsg() call must process either - only contiguous DATA records (any number of them) - one non-DATA record

If the next record has different type than what has already been processed we break out of the main processing loop. If the record has already been decrypted (which may be the case for TLS 1.3 where we don't know type until decryption) we queue the pending record to the rx_list. Next recvmsg() will pick it up from there.

Queuing the skb to rx_list after zero-copy decrypt is not possible, since in that case we decrypted directly to the user space buffer, and we don't have an skb to queue (darg.skb points to the ciphertext skb for access to metadata like length).

Only data records are allowed zero-copy, and we break the processing loop after each non-data record. So we should never zero-copy and then find out that the record type has changed. The corner case we missed is when the initial record comes from rx_list, and it's zero length.

Database specific 
{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/39xxx/CVE-2025-39682.json",
    "cna_assigner": "Linux"
}
References

Affected packages

Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Affected ranges

Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
84c61fe1a75b4255df1e1e7c054c9e6d048da417
Fixed
2902c3ebcca52ca845c03182000e8d71d3a5196f
Fixed
c09dd3773b5950e9cfb6c9b9a5f6e36d06c62677
Fixed
3439c15ae91a517cf3c650ea15a8987699416ad9
Fixed
29c0ce3c8cdb6dc5d61139c937f34cb888a6f42e
Fixed
62708b9452f8eb77513115b17c4f8d1a22ebf843

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-39682.json"