Message-ID: <2025082239-CVE-2025-38658-2dd0@gregkh>
Date: Fri, 22 Aug 2025 18:01:06 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-cve-announce@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...nel.org>
Subject: CVE-2025-38658: nvmet: pci-epf: Do not complete commands twice if nvmet_req_init() fails

From: Greg Kroah-Hartman <gregkh@...nel.org>

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

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

nvmet: pci-epf: Do not complete commands twice if nvmet_req_init() fails

Have nvmet_req_init() and req->execute() complete failed commands.

Description of the problem:
nvmet_req_init() calls __nvmet_req_complete() internally upon failure,
e.g., unsupported opcode, which calls the "queue_response" callback,
this results in nvmet_pci_epf_queue_response() being called, which will
call nvmet_pci_epf_complete_iod() if data_len is 0 or if dma_dir is
different from DMA_TO_DEVICE. This results in a double completion as
nvmet_pci_epf_exec_iod_work() also calls nvmet_pci_epf_complete_iod()
when nvmet_req_init() fails.

Steps to reproduce:
On the host send a command with an unsupported opcode with nvme-cli,
For example the admin command "security receive"
$ sudo nvme security-recv /dev/nvme0n1 -n1 -x4096

This triggers a double completion as nvmet_req_init() fails and
nvmet_pci_epf_queue_response() is called, here iod->dma_dir is still
in the default state of "DMA_NONE" as set by default in
nvmet_pci_epf_alloc_iod(), so nvmet_pci_epf_complete_iod() is called.
Because nvmet_req_init() failed nvmet_pci_epf_complete_iod() is also
called in nvmet_pci_epf_exec_iod_work() leading to a double completion.
This not only sends two completions to the host but also corrupts the
state of the PCI NVMe target leading to kernel oops.

This patch lets nvmet_req_init() and req->execute() complete all failed
commands, and removes the double completion case in
nvmet_pci_epf_exec_iod_work() therefore fixing the edge cases where
double completions occurred.

The Linux kernel CVE team has assigned CVE-2025-38658 to this issue.


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

	Issue introduced in 6.14 with commit 0faa0fe6f90ea59b10d1b0f15ce0eb0c18eff186 and fixed in 6.16.1 with commit a535c0b10060bc8c174a7964b0f98064ee0c4774
	Issue introduced in 6.14 with commit 0faa0fe6f90ea59b10d1b0f15ce0eb0c18eff186 and fixed in 6.17-rc1 with commit 746d0ac5a07d5da952ef258dd4d75f0b26c96476

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-2025-38658
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/target/pci-epf.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/a535c0b10060bc8c174a7964b0f98064ee0c4774
	https://git.kernel.org/stable/c/746d0ac5a07d5da952ef258dd4d75f0b26c96476

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