CVE-2026-52937

tap: fix stack info leak in tap_ioctl() SIOCGIFHWADDR

MEDIUM
5.5
CVSS Score
Published: June 24, 2026 at 07:14 AM UTC
Updated: October 30, 2026 at 01:19 PM UTC
1 product affected across 1 vendorLinux Kernel

Using Linux by Linux?

Get instant alerts when new vulnerabilities affect Linux - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
MEDIUM5.5
Exploit prediction
EPSS 0.1%

Description

In 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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

5.10.21 ≤ v < 5.115.11.4 ≤ v < 6.18.345.4.103 ≤ v < 5.56.19 ≤ v < 7.0.11176188cff67ec1aa55103647b61d02315cc38e981fc205d9e400f069ebf30d3faa6ec2bab2cbd7b43b23a32a63219f51a5298bc55a65ecee866e79d04d0ae760c02c98fc78b78d3a0509896bc648ad1c5.10.215.11.45.4.1037.17.1 rc17.1 rc27.1 rc37.1 rc4
Vendor states this is fixed in 05305e832be7b9d65b2b72caacf7d850b3942b2a (fixed)
Vendor states this is fixed in 719007c3492f0f1f9e9cdbed8ac45ba45bb13eeb (fixed)
Vendor states this is fixed in bddc09212c24934643bd44fc794748d2bbb3b6cd (fixed)
Affected range stops below 5.11, so it looks safe — our inference, not a vendor statement
Vendor states this is fixed in 5.12 (unaffected)
Affected range stops below 5.5, so it looks safe — our inference, not a vendor statement
Vendor states this is fixed in 6.12.114 (unaffected)
Vendor states this is fixed in 6.18.34 (unaffected)
Vendor states this is fixed in 6.6.160 (unaffected)
Vendor states this is fixed in 7.0.11 (unaffected)
Vendor states this is fixed in 7.1 (unaffected)

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-401

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card