CVE-2017-1000405

Name	CVE-2017-1000405
Description	The Linux Kernel versions 2.6.38 through 4.14 have a problematic use of pmd_mkdirty() in the touch_pmd() function inside the THP implementation. touch_pmd() can be reached by get_user_pages(). In such case, the pmd will become dirty. This scenario breaks the new can_follow_write_pmd()'s logic - pmd can become dirty without going through a COW cycle. This bug is not as severe as the original "Dirty cow" because an ext4 file (or any other regular file) cannot be mapped using THP. Nevertheless, it does allow us to overwrite read-only huge pages. For example, the zero huge page and sealed shmem files can be overwritten (since their mapping can be populated using THP). Note that after the first write page-fault to the zero page, it will be replaced with a new fresh (and zeroed) thp.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, 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)	buster	4.19.249-2	fixed
	buster (security)	4.19.304-1	fixed
	bullseye	5.10.209-2	fixed
	bullseye (security)	5.10.205-2	fixed
	bookworm	6.1.76-1	fixed
	bookworm (security)	6.1.85-1	fixed
	trixie	6.6.15-2	fixed
	sid	6.7.9-2	fixed

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

Package	Type	Release	Fixed Version
linux	source	wheezy	(not affected)
linux	source	jessie	3.16.51-1
linux	source	stretch	4.9.65-1
linux	source	(unstable)	4.14.2-1

Notes

[wheezy] - linux <not-affected> (vulnerable code not present, cf. kernel-sec information)
Fixed by: https://git.kernel.org/linus/a8f97366452ed491d13cf1e44241bc0b5740b1f0
https://www.openwall.com/lists/oss-security/2017/11/30/1
https://github.com/bindecy/HugeDirtyCowPOC