CVE-2024-26844

Name	CVE-2024-26844
Description	In the Linux kernel, the following vulnerability has been resolved: block: Fix WARNING in _copy_from_iter Syzkaller reports a warning in _copy_from_iter because an iov_iter is supposedly used in the wrong direction. The reason is that syzcaller managed to generate a request with a transfer direction of SG_DXFER_TO_FROM_DEV. This instructs the kernel to copy user buffers into the kernel, read into the copied buffers and then copy the data back to user space. Thus the iovec is used in both directions. Detect this situation in the block layer and construct a new iterator with the correct direction for the copy-in.
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)	jessie, jessie (lts)	3.16.84-1	vulnerable
	stretch (security)	4.9.320-2	vulnerable
	stretch (lts), stretch	4.9.320-3	vulnerable
	buster (security), buster, buster (lts)	4.19.316-1	vulnerable
	bullseye	5.10.223-1	vulnerable
	bullseye (security)	5.10.226-1	vulnerable
	bookworm	6.1.115-1	fixed
	bookworm (security)	6.1.119-1	fixed
	trixie	6.12.5-1	fixed
	sid	6.12.6-1	fixed

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

Package	Type	Release	Fixed Version	Urgency
linux	source	jessie	(unfixed)	end-of-life
linux	source	stretch	(unfixed)	end-of-life
linux	source	buster	(unfixed)	end-of-life
linux	source	bookworm	6.1.82-1
linux	source	(unstable)	6.7.7-1

https://git.kernel.org/linus/13f3956eb5681a4045a8dfdef48df5dc4d9f58a6 (6.8-rc2)