CVE-2022-48630: crypto: qcom-rng - fix infinite loop on requests not multiple of WORD_SZ

CVE-2022-48630: crypto: qcom-rng - fix infinite loop on requests not multiple of WORD_SZ

[Greg Kroah-Hartman]

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

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

crypto: qcom-rng - fix infinite loop on requests not multiple of WORD_SZ

The commit referenced in the Fixes tag removed the 'break' from the else
branch in qcom_rng_read(), causing an infinite loop whenever 'max' is
not a multiple of WORD_SZ. This can be reproduced e.g. by running:

    kcapi-rng -b 67 >/dev/null

There are many ways to fix this without adding back the 'break', but
they all seem more awkward than simply adding it back, so do just that.

Tested on a machine with Qualcomm Amberwing processor.

The Linux kernel CVE team has assigned CVE-2022-48630 to this issue.


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

	Issue introduced in 4.19.236 with commit a8e32bbb96c2 and fixed in 4.19.245 with commit 71a89789552b
	Issue introduced in 5.4.187 with commit 184f7bd08ce5 and fixed in 5.4.196 with commit 8be06f62b426
	Issue introduced in 5.10.108 with commit 0f9b7b8df175 and fixed in 5.10.118 with commit 233a3cc60e7a
	Issue introduced in 5.15.31 with commit ab9337c7cb6f and fixed in 5.15.42 with commit 8a06f25f5941
	Issue introduced in 5.17 with commit a680b1832ced and fixed in 5.17.10 with commit 05d4d17475d8
	Issue introduced in 5.17 with commit a680b1832ced and fixed in 5.18 with commit 16287397ec5c

Please see https://www.kernel.org or 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-2022-48630
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:
	drivers/crypto/qcom-rng.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/71a89789552b7faf3ef27969b9bc783fa0df3550
	https://git.kernel.org/stable/c/8be06f62b426801dba43ddf8893952a0e62ab6ae
	https://git.kernel.org/stable/c/233a3cc60e7a8fe0be8cf9934ae7b67ba25a866c
	https://git.kernel.org/stable/c/8a06f25f5941c145773204f2f7abef95b4ffb8ce
	https://git.kernel.org/stable/c/05d4d17475d8d094c519bb51658bc47899c175e3
	https://git.kernel.org/stable/c/16287397ec5c08aa58db6acf7dbc55470d78087d