CVE-2026-80787
Received Received - Intake

Use-After-Free in Linux Kernel NVMe Target PCI EPF Driver

Publication date: 2026-09-04

Last updated on: 2026-09-04

Assigner: 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.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published
2026-09-04
Last Modified
2026-09-04
Generated
2026-09-04
AI Q&A
2026-09-04
EPSS Evaluated
N/A
NVD
CVE-2026-80787
EUVD
EUVD-2026-71430

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
linux_kernel nvmet *

Helpful Resources

Exploitability

CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-UNKNOWN

Attack-Flow Graph

AI Quick Actions

Instant insights powered by AI
Executive Summary

This is a use-after-free vulnerability in the Linux kernel's NVMe over Fabrics (NVMe-oF) target subsystem. The issue occurs in the nvmet_pci_epf_exec_iod_work() function when handling I/O commands. The function submits a command and then checks iod->data_len and iod->dma_dir to determine if a wait is needed for data transfer. However, the command may complete asynchronously on another CPU, causing the iod structure to be freed before these fields are read, leading to a use-after-free error.

Detection Guidance

This vulnerability is specific to the Linux kernel's NVMe over Fabrics (NVMe-oF) target implementation. Detection requires checking kernel logs for use-after-free errors related to nvmet_pci_epf_exec_iod_work. Monitor dmesg or system logs for KFENCE warnings or kernel oops messages indicating memory corruption in the nvmet_pci_epf module.

Impact Analysis

This vulnerability could allow an attacker with local access to cause a kernel crash or potentially execute arbitrary code with kernel privileges. It may lead to system instability, data corruption, or unauthorized access depending on the attacker's capabilities and system configuration.

Mitigation Strategies

Apply the kernel patch that fixes the use-after-free issue in nvmet_pci_epf_exec_iod_work. Update to a Linux kernel version that includes the fix. If immediate patching is not possible, disable NVMe-oF target functionality temporarily until the patch is applied.

Chat Assistant

Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-80787. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70

EPSS Chart