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.
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.
Metrics
Affected Vendors & Products
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Fri, 04 Sep 2026 15:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | nvmet: pci-epf: fix use-after-free in nvmet_pci_epf_exec_iod_work() | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-04T15:12:58.796Z
Reserved: 2026-08-26T14:34:25.793Z
Link: CVE-2026-80787
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-04T16:18:04.710
Modified: 2026-09-04T16:18:04.710
Link: CVE-2026-80787
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.