Subject: CVE-2024-38614: openrisc: traps: Don't send signals to kernel mode threads

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

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

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

openrisc: traps: Don't send signals to kernel mode threads

OpenRISC exception handling sends signals to user processes on floating
point exceptions and trap instructions (for debugging) among others.
There is a bug where the trap handling logic may send signals to kernel
threads, we should not send these signals to kernel threads, if that
happens we treat it as an error.

This patch adds conditions to die if the kernel receives these
exceptions in kernel mode code.

The Linux kernel CVE team has assigned CVE-2024-38614 to this issue.

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

	Issue introduced in 6.4 with commit 27267655c531 and fixed in 6.6.33 with commit c0ed9a711e33
	Issue introduced in 6.4 with commit 27267655c531 and fixed in 6.8.12 with commit 075c0405b0d7
	Issue introduced in 6.4 with commit 27267655c531 and fixed in 6.9.3 with commit cea9d0015c14
	Issue introduced in 6.4 with commit 27267655c531 and fixed in 6.10 with commit c88cfb5cea5f

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-2024-38614
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:
	arch/openrisc/kernel/traps.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/c0ed9a711e3392d73e857faa031d8d349c0d70db
	https://git.kernel.org/stable/c/075c0405b0d7d9fc490609e988a3af0069596538
	https://git.kernel.org/stable/c/cea9d0015c140af39477dd5eeb9b20233a45daa9
	https://git.kernel.org/stable/c/c88cfb5cea5f8f9868ef02cc9ce9183a26dcf20f