Subject: CVE-2023-52774: s390/dasd: protect device queue against concurrent access

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

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

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

s390/dasd: protect device queue against concurrent access

In dasd_profile_start() the amount of requests on the device queue are
counted. The access to the device queue is unprotected against
concurrent access. With a lot of parallel I/O, especially with alias
devices enabled, the device queue can change while dasd_profile_start()
is accessing the queue. In the worst case this leads to a kernel panic
due to incorrect pointer accesses.

Fix this by taking the device lock before accessing the queue and
counting the requests. Additionally the check for a valid profile data
pointer can be done earlier to avoid unnecessary locking in a hot path.

The Linux kernel CVE team has assigned CVE-2023-52774 to this issue.

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

	Issue introduced in 3.1 with commit 4fa52aa7a82f and fixed in 4.14.332 with commit ebdc569a07a3
	Issue introduced in 3.1 with commit 4fa52aa7a82f and fixed in 4.19.301 with commit f75617cc8df4
	Issue introduced in 3.1 with commit 4fa52aa7a82f and fixed in 5.4.263 with commit f1ac7789406e
	Issue introduced in 3.1 with commit 4fa52aa7a82f and fixed in 5.10.203 with commit c841de6247e9
	Issue introduced in 3.1 with commit 4fa52aa7a82f and fixed in 5.15.141 with commit 6062c527d040
	Issue introduced in 3.1 with commit 4fa52aa7a82f and fixed in 6.1.65 with commit dc96fde8fcb2
	Issue introduced in 3.1 with commit 4fa52aa7a82f and fixed in 6.6.4 with commit 9372aab5d0ff
	Issue introduced in 3.1 with commit 4fa52aa7a82f and fixed in 6.7 with commit db46cd1e0426

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-2023-52774
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/s390/block/dasd.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/ebdc569a07a3e8dbe66b4184922ad6f88ac0b96f
	https://git.kernel.org/stable/c/f75617cc8df4155374132f0b500b0b3ebb967458
	https://git.kernel.org/stable/c/f1ac7789406e2ca9ac51c41ad2daa597f47bdd4d
	https://git.kernel.org/stable/c/c841de6247e94e07566d57163d3c0d8b29278f7a
	https://git.kernel.org/stable/c/6062c527d0403cef27c54b91ac8390c3a497b250
	https://git.kernel.org/stable/c/dc96fde8fcb2b896fd6c64802a7f4ece2e69b0be
	https://git.kernel.org/stable/c/9372aab5d0ff621ea203c8c603e7e5f75e888240
	https://git.kernel.org/stable/c/db46cd1e0426f52999d50fa72cfa97fa39952885