Subject: CVE-2022-48730: dma-buf: heaps: Fix potential spectre v1 gadget

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

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

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

dma-buf: heaps: Fix potential spectre v1 gadget

It appears like nr could be a Spectre v1 gadget as it's supplied by a
user and used as an array index. Prevent the contents
of kernel memory from being leaked to userspace via speculative
execution by using array_index_nospec.

 [sumits: added fixes and cc: stable tags]

The Linux kernel CVE team has assigned CVE-2022-48730 to this issue.

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

	Issue introduced in 5.6 with commit c02a81fba74f and fixed in 5.10.99 with commit 5d40f1bdad3d
	Issue introduced in 5.6 with commit c02a81fba74f and fixed in 5.15.22 with commit 24f8e12d965b
	Issue introduced in 5.6 with commit c02a81fba74f and fixed in 5.16.8 with commit cc8f7940d9c2
	Issue introduced in 5.6 with commit c02a81fba74f and fixed in 5.17 with commit 92c4cfaee687

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-2022-48730
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/dma-buf/dma-heap.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/5d40f1bdad3dd1a177f21a90ad4353c1ed40ba3a
	https://git.kernel.org/stable/c/24f8e12d965b24f8aea762589e0e9fe2025c005e
	https://git.kernel.org/stable/c/cc8f7940d9c2d45f67b3d1a2f2b7a829ca561bed
	https://git.kernel.org/stable/c/92c4cfaee6872038563c5b6f2e8e613f9d84d47d