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.
Fix
Patch, vendor advisory and mitigation references on NVD 3
- https://git.kernel.org/stable/c/05305e832be7b9d65b2b72caacf7d850b3942b2a Patch
- https://git.kernel.org/stable/c/719007c3492f0f1f9e9cdbed8ac45ba45bb13eeb Patch
- https://git.kernel.org/stable/c/bddc09212c24934643bd44fc794748d2bbb3b6cd Patch
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 5
- CwesCWE-401NVD modified 2026-10-21 13:19
- Cpes+5 CPE criteria (now 5)NVD modified 2026-10-21 13:19
- StatusPublished → ModifiedNVD modified 2026-10-21 13:19
- CVSS5.5 (v3.1, CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)NVD modified 2026-10-21 13:19
- First seenunscored · linuxNVD modified 2026-10-21 12:41
Affected (CPE criteria) 5
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:*
References 5
- https://git.kernel.org/stable/c/05305e832be7b9d65b2b72caacf7d850b3942b2a Patch
- https://git.kernel.org/stable/c/37d028a473b0826ad5970b52b791db4a29a23627
- https://git.kernel.org/stable/c/719007c3492f0f1f9e9cdbed8ac45ba45bb13eeb Patch
- https://git.kernel.org/stable/c/8197905d97099d8b1e3883112bbb497abd20f9f0
- https://git.kernel.org/stable/c/bddc09212c24934643bd44fc794748d2bbb3b6cd Patch