From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-cve-announce@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@kernel.org>
Subject: CVE-2026-80787: nvmet: pci-epf: fix use-after-free in nvmet_pci_epf_exec_iod_work()
Date: Fri, 4 Sep 2026 17:11:26 +0200 [thread overview]
Message-ID: <2026090405-CVE-2026-80787-d0b7@gregkh> (raw)
From: Greg Kroah-Hartman <gregkh@kernel.org>
Description
===========
In the Linux kernel, the following vulnerability has been resolved:
nvmet: pci-epf: fix use-after-free in nvmet_pci_epf_exec_iod_work()
nvmet_pci_epf_exec_iod_work() submits an I/O command with req->execute()
and then waits for the command to complete and transfers the data back
to the host. This wait is not needed for commands that do not transfer
data from the device to the host. To decide whether that wait is needed,
it reads iod->data_len and iod->dma_dir after calling req->execute().
However, once req->execute() is called, the command may complete
asynchronously on another CPU. For commands that do not require a
device-to-host data transfer, nvmet_pci_epf_queue_response() calls
nvmet_pci_epf_complete_iod() directly, which can free the iod before it
reads iod->data_len and iod->dma_dir, resulting in the KFENCE use-after-
free:
BUG: KFENCE: use-after-free read in nvmet_pci_epf_exec_iod_work+0x288/0x798 [nvmet_pci_epf]
Use-after-free read at 0x00000000fdfa6d03 (in kfence-#63):
nvmet_pci_epf_exec_iod_work+0x288/0x798 [nvmet_pci_epf]
process_one_work+0x15c/0x4f0
worker_thread+0x18c/0x30c
kthread+0x130/0x140
ret_from_fork+0x10/0x20
kfence-#63: 0x00000000e3de0e71-0x00000000c938ad62, size=712, cache=kmalloc-1k
allocated by task 10 on cpu 0 at 73.995480s (0.005122s ago):
mempool_kmalloc+0x1c/0x28
mempool_alloc_noprof+0x40/0x9c
nvmet_pci_epf_poll_sqs_work+0xd4/0x344 [nvmet_pci_epf]
process_one_work+0x15c/0x4f0
worker_thread+0x18c/0x30c
kthread+0x130/0x140
ret_from_fork+0x10/0x20
freed by task 131 on cpu 3 at 73.995521s (0.008385s ago):
mempool_kfree+0x10/0x20
mempool_free+0x44/0x64
nvmet_pci_epf_free_iod+0x88/0x98 [nvmet_pci_epf]
nvmet_pci_epf_cq_work+0xfc/0x280 [nvmet_pci_epf]
process_one_work+0x15c/0x4f0
worker_thread+0x18c/0x30c
kthread+0x130/0x140
ret_from_fork+0x10/0x20
Fix this by referring to iod->data_len and iod->dma_dir before calling
req->execute(). The remaining iod accesses such as iod->status are only
reached on the device-to-host read path. In this case,
nvmet_pci_epf_queue_response() signals iod->done instead of freeing the
iod, so the iod stays valid.
The Linux kernel CVE team has assigned CVE-2026-80787 to this issue.
Affected and fixed versions
===========================
Issue introduced in 6.14 with commit 0faa0fe6f90ea59b10d1b0f15ce0eb0c18eff186 and fixed in 6.18.47 with commit 20be486d1c225402b067391e72ff5b0dd8ebff76
Issue introduced in 6.14 with commit 0faa0fe6f90ea59b10d1b0f15ce0eb0c18eff186 and fixed in 7.1.11 with commit 1ed1eeaef55cebf2d74b3ef104c20bdab719b165
Issue introduced in 6.14 with commit 0faa0fe6f90ea59b10d1b0f15ce0eb0c18eff186 and fixed in 7.2.1 with commit cede8d2852570c79b9bbb9527255ae9ed3317b82
Issue introduced in 6.14 with commit 0faa0fe6f90ea59b10d1b0f15ce0eb0c18eff186 and fixed in 7.3-rc1 with commit c9e9bb757971485b4e8414b1744507af186d72c9
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-2026-80787
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/20be486d1c225402b067391e72ff5b0dd8ebff76
https://git.kernel.org/stable/c/1ed1eeaef55cebf2d74b3ef104c20bdab719b165
https://git.kernel.org/stable/c/cede8d2852570c79b9bbb9527255ae9ed3317b82
https://git.kernel.org/stable/c/c9e9bb757971485b4e8414b1744507af186d72c9
reply other threads:[~2026-09-04 15:16 UTC|newest]
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