tcp: Fix potential UAF in reqsk_timer_handler().

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-99270
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-11-03 13:17:24 UTC
Updated2026-11-06 18:18:33 UTC
DescriptionIn the Linux kernel, the following vulnerability has been resolved: tcp: Fix potential UAF in reqsk_timer_handler(). When TCP socket migration fails at inet_ehash_insert() in reqsk_timer_handler(), we jump to the no_ownership: label and free the new reqsk immediately with __reqsk_free(). Thus, we must stop the new reqsk's timer before jumping to the label, but the timer might be missed since the cited commit, resulting in UAF. As we are in the original reqsk's timer context, we can safely call timer_delete_sync() for the new reqsk. Let's pass false to __inet_csk_reqsk_queue_drop() to stop the new reqsk's timer.

Risk And Classification

Primary CVSS: v3.1 8.1 HIGH from 416baaa9-dc9f-4396-8d5f-8c081fb06d67

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

VersionSourceTypeScoreSeverityVector
3.1416baaa9-dc9f-4396-8d5f-8c081fb06d67Secondary8.1HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
3.1CNADECLARED8.1HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected 83fccfc3940c4a2db90fd7e7079f5b465cd8c6af b3b56e95f6fad7fa7281450b443e861d82616fdb git Not specified
CNA Linux Linux affected 83fccfc3940c4a2db90fd7e7079f5b465cd8c6af 97c8a3c1f73d828de43a5a88e8a9a143efb2b661 git Not specified
CNA Linux Linux affected d3a1196bfc462943694623412d8e03aaf172bdc1 git Not specified
CNA Linux Linux affected 4.1.11 4.2 semver Not specified
CNA Linux Linux affected 4.2 Not specified
CNA Linux Linux unaffected 4.2 semver Not specified
CNA Linux Linux unaffected 6.18.61 6.18.* semver Not specified
CNA Linux Linux unaffected 7.1 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/97c8a3c1f73d828de43a5a88e8a9a143efb2b661 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/b3b56e95f6fad7fa7281450b443e861d82616fdb 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
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