Subject: CVE-2022-48747: block: Fix wrong offset in bio_truncate()

From: Greg Kroah-Hartman <[email-masked]>

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

block: Fix wrong offset in bio_truncate()

bio_truncate() clears the buffer outside of last block of bdev, however
current bio_truncate() is using the wrong offset of page. So it can
return the uninitialized data.

This happened when both of truncated/corrupted FS and userspace (via
bdev) are trying to read the last of bdev.

The Linux kernel CVE team has assigned CVE-2022-48747 to this issue.

Affected and fixed versions
===========================

	Fixed in 5.4.176 with commit 6cbf4c731d78
	Fixed in 5.10.96 with commit b63e120189fd
	Fixed in 5.15.19 with commit 4633a79ff8bc
	Fixed in 5.16.5 with commit 941d5180c430
	Fixed in 5.17 with commit 3ee859e384d4

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2022-48747
will be updated if fixes are backported, please check that for the most
up to date information about this issue.

Affected files
==============

The file(s) affected by this issue are:
	block/bio.c

Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/6cbf4c731d7812518cd857c2cfc3da9fd120f6ae
	https://git.kernel.org/stable/c/b63e120189fd92aff00096d11e2fc5253f60248b
	https://git.kernel.org/stable/c/4633a79ff8bc82770486a063a08b55e5162521d8
	https://git.kernel.org/stable/c/941d5180c430ce5b0f7a3622ef9b76077bfa3d82
	https://git.kernel.org/stable/c/3ee859e384d453d6ac68bfd5971f630d9fa46ad3