Subject: CVE-2024-41082: nvme-fabrics: use reserved tag for reg read/write command

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

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

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

nvme-fabrics: use reserved tag for reg read/write command

In some scenarios, if too many commands are issued by nvme command in
the same time by user tasks, this may exhaust all tags of admin_q. If
a reset (nvme reset or IO timeout) occurs before these commands finish,
reconnect routine may fail to update nvme regs due to insufficient tags,
which will cause kernel hang forever. In order to workaround this issue,
maybe we can let reg_read32()/reg_read64()/reg_write32() use reserved
tags. This maybe safe for nvmf:

1. For the disable ctrl path,  we will not issue connect command
2. For the enable ctrl / fw activate path, since connect and reg_xx()
   are called serially.

So the reserved tags may still be enough while reg_xx() use reserved tags.

The Linux kernel CVE team has assigned CVE-2024-41082 to this issue.

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

	Fixed in 6.9.11 with commit 165da9c67a26
	Fixed in 6.10 with commit 7dc3bfcb4c9c

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-2024-41082
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/nvme/host/fabrics.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/165da9c67a26f08c9b956c15d701da7690f45bcb
	https://git.kernel.org/stable/c/7dc3bfcb4c9cc58970fff6aaa48172cb224d85aa