net: microchip: vcap: fix races on the shared Super VCAP block

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-72340
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-08-15 06:22:07 UTC
Updated2026-08-17 06:18:37 UTC
DescriptionIn the Linux kernel, the following vulnerability has been resolved: net: microchip: vcap: fix races on the shared Super VCAP block The VCAP instances on a chip are not independent, yet they are locked independently. On sparx5 and lan969x the IS0 and IS2 instances are backed by the same Super VCAP hardware block and share its cache and command registers: every access drives the shared VCAP_SUPER_CTRL register and moves data through the shared cache registers. Accessing one instance therefore races with accessing another. The per-instance admin->lock cannot prevent this, as each instance takes a different lock. The locking issue is mostly disguised by the fact that the core usage of the vcap api runs under rtnl. However, the full rule dump in debugfs decodes rules straight from hardware (a READ command followed by a cache read) and runs outside rtnl, so it races a concurrent tc-flower rule write to another Super VCAP instance. Besides corrupting the dump, the read repopulates the shared cache between the writers cache fill and its write command, so the writer commits the wrong data and corrupts the hardware entry. Introduce vcap_lock() and vcap_unlock() helpers and route every rule lock site in the VCAP API and its debugfs code through them. Replace the per-instance admin->lock with a single mutex in struct vcap_control that serializes access to all instances. The helpers reach it through a new admin->vctrl back-pointer, and the clients initialise and destroy the control lock instead of a per-instance one. No path holds more than one instance lock, so collapsing them onto a single mutex cannot self-deadlock.

Risk And Classification

Primary CVSS: v3.1 7.8 HIGH from 416baaa9-dc9f-4396-8d5f-8c081fb06d67

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

EPSS: 0.001750000 probability, percentile 0.073120000 (date 2026-08-17)

VersionSourceTypeScoreSeverityVector
3.1416baaa9-dc9f-4396-8d5f-8c081fb06d67Secondary7.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
3.1CNADECLARED7.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS v3.1 Breakdown

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

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

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected 71c9de995260222e739020104d477af4775a6d26 786456d0a244bbd405dfc60e4de51f8b348b9cb1 git Not specified
CNA Linux Linux affected 71c9de995260222e739020104d477af4775a6d26 49806bef9572a2e012610517bc14ed0a4db0d1fc git Not specified
CNA Linux Linux affected 71c9de995260222e739020104d477af4775a6d26 1e71a40d101547380590db582213c1f1dce1f041 git Not specified
CNA Linux Linux affected 71c9de995260222e739020104d477af4775a6d26 952928564cc5fdb06f92d7e25c6cd2e1d816362b git Not specified
CNA Linux Linux affected 71c9de995260222e739020104d477af4775a6d26 d7a8d500d7e42837bd8dce40cb52c97c6e8706a9 git Not specified
CNA Linux Linux affected 6.2 Not specified
CNA Linux Linux unaffected 6.2 semver Not specified
CNA Linux Linux unaffected 6.6.145 6.6.* semver Not specified
CNA Linux Linux unaffected 6.12.97 6.12.* semver Not specified
CNA Linux Linux unaffected 6.18.40 6.18.* semver Not specified
CNA Linux Linux unaffected 7.1.5 7.1.* semver Not specified
CNA Linux Linux unaffected 7.2 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/49806bef9572a2e012610517bc14ed0a4db0d1fc 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/952928564cc5fdb06f92d7e25c6cd2e1d816362b 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/d7a8d500d7e42837bd8dce40cb52c97c6e8706a9 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/1e71a40d101547380590db582213c1f1dce1f041 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/786456d0a244bbd405dfc60e4de51f8b348b9cb1 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
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