CVE-2026-52937

Summary

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 Software

VendorProductVersion RangeStatus
LinuxLinux3b23a32a63219f51a5298bc55a65ecee866e79d0 < 719007c3492f0f1f9e9cdbed8ac45ba45bb13eebaffected
LinuxLinux3b23a32a63219f51a5298bc55a65ecee866e79d0 < 05305e832be7b9d65b2b72caacf7d850b3942b2aaffected
LinuxLinux3b23a32a63219f51a5298bc55a65ecee866e79d0 < bddc09212c24934643bd44fc794748d2bbb3b6cdaffected
LinuxLinux176188cff67ec1aa55103647b61d02315cc38e98affected
LinuxLinux1fc205d9e400f069ebf30d3faa6ec2bab2cbd7b4affected
LinuxLinux4d0ae760c02c98fc78b78d3a0509896bc648ad1caffected
LinuxLinux5.4.103 < 5.5affected
LinuxLinux5.10.21 < 5.11affected
LinuxLinux5.11.4 < 5.12affected
LinuxLinux5.12affected
LinuxLinux0 < 5.12unaffected
LinuxLinux6.18.34 <= 6.18.*unaffected
LinuxLinux7.0.11 <= 7.0.*unaffected
LinuxLinux7.1 <= *unaffected

Weaknesses

References