CVE-2026-52937

Name	CVE-2026-52937
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.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
linux (PTS)	bullseye	5.10.223-1	vulnerable
	bullseye (security)	5.10.257-1	vulnerable
	bookworm	6.1.170-3	vulnerable
	bookworm (security)	6.1.174-1	vulnerable
	trixie	6.12.86-1	vulnerable
	trixie (security)	6.12.94-1	vulnerable
	forky	7.0.12-2	fixed
	sid	7.0.13-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
linux	source	(unstable)	7.0.12-1

https://git.kernel.org/linus/bddc09212c24934643bd44fc794748d2bbb3b6cd (7.1-rc5)