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.
Metrics
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux | >= 3b23a32a63219f51a5298bc55a65ecee866e79d0, < 4b6dcfe0e3dfffd8057a4fc99b3f096c45709905; >= 3b23a32a63219f51a5298bc55a65ecee866e79d0, < 37d028a473b0826ad5970b52b791db4a29a23627; >= 3b23a32a63219f51a5298bc55a65ecee866e79d0, < 8197905d97099d8b1e3883112bbb497abd20f9f0; >= 3b23a32a63219f51a5298bc55a65ecee866e79d0, < 719007c3492f0f1f9e9cdbed8ac45ba45bb13eeb; >= 3b23a32a63219f51a5298bc55a65ecee866e79d0, < 05305e832be7b9d65b2b72caacf7d850b3942b2a; >= 3b23a32a63219f51a5298bc55a65ecee866e79d0, < bddc09212c24934643bd44fc794748d2bbb3b6cd; 176188cff67ec1aa55103647b61d02315cc38e98; 1fc205d9e400f069ebf30d3faa6ec2bab2cbd7b4; 4d0ae760c02c98fc78b78d3a0509896bc648ad1c; >= 5.4.103, < 5.5; >= 5.10.21, < 5.11; >= 5.11.4, < 5.12 |
| Linux | Linux | 5.12 |
References
- https://git.kernel.org/stable/c/05305e832be7b9d65b2b72caacf7d850b3942b2aPatch
- https://git.kernel.org/stable/c/37d028a473b0826ad5970b52b791db4a29a23627
- https://git.kernel.org/stable/c/4b6dcfe0e3dfffd8057a4fc99b3f096c45709905
- https://git.kernel.org/stable/c/719007c3492f0f1f9e9cdbed8ac45ba45bb13eebPatch
- https://git.kernel.org/stable/c/8197905d97099d8b1e3883112bbb497abd20f9f0
- https://git.kernel.org/stable/c/bddc09212c24934643bd44fc794748d2bbb3b6cdPatch
Timeline
- Published
- Jun 24, 2026
- Last modified
- Nov 6, 2026
- NVD status
- Modified