tap: fix stack info leak in tap_ioctl() SIOCGIFHWADDR

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-52937
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-06-24 08:16:23 UTC
Updated2026-07-08 19:22:42 UTC
DescriptionIn the Linux kernel, the following vulnerability has been resolved: tap: fix stack info leak in tap_ioctl() SIOCGIFHWADDR In the SIOCGIFHWADDR path, tap_ioctl() copies 16 bytes of an uninitialised on-stack struct sockaddr_storage to userspace via ifr_hwaddr, but netif_get_mac_address() only writes sa_family and dev->addr_len (6 for Ethernet) bytes, leaving sa_data[6..13] uninitialised. Those 8 trailing bytes leak kernel stack contents; SIOCGIFHWADDR on a macvtap chardev returns kernel .text and direct-map pointers, defeating KASLR. Initialise ss at declaration.

Risk And Classification

Primary CVSS: v3.1 5.5 MEDIUM from [email protected]

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

EPSS: 0.001120000 probability, percentile 0.016450000 (date 2026-07-09)

Problem Types: CWE-401

CVSS v3.1 Breakdown

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

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

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Operating System Linux Linux Kernel All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected 3b23a32a63219f51a5298bc55a65ecee866e79d0 719007c3492f0f1f9e9cdbed8ac45ba45bb13eeb git Not specified
CNA Linux Linux affected 3b23a32a63219f51a5298bc55a65ecee866e79d0 05305e832be7b9d65b2b72caacf7d850b3942b2a git Not specified
CNA Linux Linux affected 3b23a32a63219f51a5298bc55a65ecee866e79d0 bddc09212c24934643bd44fc794748d2bbb3b6cd git Not specified
CNA Linux Linux affected 176188cff67ec1aa55103647b61d02315cc38e98 git Not specified
CNA Linux Linux affected 1fc205d9e400f069ebf30d3faa6ec2bab2cbd7b4 git Not specified
CNA Linux Linux affected 4d0ae760c02c98fc78b78d3a0509896bc648ad1c git Not specified
CNA Linux Linux affected 5.4.103 5.5 semver Not specified
CNA Linux Linux affected 5.10.21 5.11 semver Not specified
CNA Linux Linux affected 5.11.4 5.12 semver Not specified
CNA Linux Linux affected 5.12 Not specified
CNA Linux Linux unaffected 5.12 semver Not specified
CNA Linux Linux unaffected 6.18.34 6.18.* semver Not specified
CNA Linux Linux unaffected 7.0.11 7.0.* semver Not specified
CNA Linux Linux unaffected 7.1 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/bddc09212c24934643bd44fc794748d2bbb3b6cd 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/719007c3492f0f1f9e9cdbed8ac45ba45bb13eeb 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/05305e832be7b9d65b2b72caacf7d850b3942b2a 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
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