CVE-2021-47496 (GCVE-0-2021-47496)
Vulnerability from cvelistv5 – Published: 2024-05-22 08:19 – Updated: 2026-08-05 08:48
VLAI
EPSS
VEX
Title
net/tls: Fix flipped sign in tls_err_abort() calls
Summary
In the Linux kernel, the following vulnerability has been resolved:
net/tls: Fix flipped sign in tls_err_abort() calls
sk->sk_err appears to expect a positive value, a convention that ktls
doesn't always follow and that leads to memory corruption in other code.
For instance,
[kworker]
tls_encrypt_done(..., err=<negative error from crypto request>)
tls_err_abort(.., err)
sk->sk_err = err;
[task]
splice_from_pipe_feed
...
tls_sw_do_sendpage
if (sk->sk_err) {
ret = -sk->sk_err; // ret is positive
splice_from_pipe_feed (continued)
ret = actor(...) // ret is still positive and interpreted as bytes
// written, resulting in underflow of buf->len and
// sd->len, leading to huge buf->offset and bogus
// addresses computed in later calls to actor()
Fix all tls_err_abort() callers to pass a negative error code
consistently and centralize the error-prone sign flip there, throwing in
a warning to catch future misuse and uninlining the function so it
really does only warn once.
Severity
9.8 (Critical)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2024-09-10 15:35 UTC
Assigner
References
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
c46234ebb4d1eee5e09819f49169e51cfc6eb909 , < e0cfd5159f314d6b304d030363650b06a2299cbb
(git)
Affected: c46234ebb4d1eee5e09819f49169e51cfc6eb909 , < f3dec7e7ace38224f82cf83f0049159d067c2e19 (git) Affected: c46234ebb4d1eee5e09819f49169e51cfc6eb909 , < e41473543f75f7dbc5d605007e6f883f1bd13b9a (git) Affected: c46234ebb4d1eee5e09819f49169e51cfc6eb909 , < da353fac65fede6b8b4cfe207f0d9408e3121105 (git) |
guessed | |
| Linux | Linux |
Affected:
4.17
Unaffected: 0 , < 4.17 (semver) Unaffected: 5.4.157 , ≤ 5.4.* (semver) Unaffected: 5.10.77 , ≤ 5.10.* (semver) Unaffected: 5.14.16 , ≤ 5.14.* (semver) Unaffected: 5.15 , ≤ * (original_commit_for_fix) |
guessed |
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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