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

nvme-pci: fix use-after-free in nvme_free_host_mem()

nvme_free_host_mem() frees dev->hmb_sgt via dma_free_noncontiguous()
but never clears the pointer afterward. This leads to a use-after-free
if nvme_free_host_mem() is called twice in the same error path.

This can happen during nvme_probe() when nvme_setup_host_mem() succeeds
in allocating the HMB (setting dev->hmb_sgt) but nvme_set_host_mem()
fails with an I/O error:

nvme_setup_host_mem()
nvme_alloc_host_mem_single() -> sets dev->hmb_sgt
nvme_set_host_mem() -> fails with -EIO
nvme_free_host_mem() -> frees hmb_sgt, but does NOT NULL it
return error

nvme_probe() error path:
nvme_free_host_mem() -> dev->hmb_sgt is stale, use-after-free

The second call dereferences the freed sgt, causing a NULL pointer
dereference in iommu_dma_free_noncontiguous() when it accesses
sgt->sgl->dma_address (the backing memory has been freed and zeroed).

This is reproducible on Thunderbolt-attached NVMe devices (e.g., OWC
Envoy Express behind a Dell WD22TB4 dock) where the device intermittently
returns I/O errors during HMB setup due to PCIe link instability.

BUG: kernel NULL pointer dereference, address: 0000000000000010
RIP: 0010:iommu_dma_free_noncontiguous+0x22/0x80
Call Trace:
<TASK>
dma_free_noncontiguous+0x3b/0x130
nvme_free_host_mem+0x30/0xf0 [nvme]
nvme_probe.cold+0xcc/0x275 [nvme]
local_pci_probe+0x43/0xa0
pci_device_probe+0xeea/0x290
really_probe+0xf9/0x3b0
__driver_probe_device+0x8b/0x170
driver_probe_device+0x24/0xd0
__driver_attach_async_helper+0x6b/0x110
async_run_entry_fn+0x37/0x170
process_one_work+0x1ac/0x3d0
worker_thread+0x1b8/0x360
kthread+0xf7/0x130
ret_from_fork+0x2d8/0x3a0
ret_from_fork_asm+0x1a/0x30
</TASK>

Fix this by setting dev->hmb_sgt to NULL after freeing it, so the
second call takes the multi-descriptor path which safely handles the
already-cleaned-up state.

No CVSS v4.0

Attack Vector Local

Attack Complexity High

Privileges Required Low

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00173.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
Linux Linux unaffected
Version Status Constraints
63a5c7a4b4c49ad86c362e9f555e6f343804ee1d affected < 9525e3a6fbb1d126a22ab2ee86ddea25af581a7c
63a5c7a4b4c49ad86c362e9f555e6f343804ee1d affected < 7c89f474005d8377525d2991930b7432ee193a52
63a5c7a4b4c49ad86c362e9f555e6f343804ee1d affected < b35a13036755c5803168a7cb93bc66035c3e65b8
Linux Linux affected
Version Status Constraints
6.13 affected —
0 unaffected < 6.13
6.18.34 unaffected ≤ 6.18.*
7.0.11 unaffected ≤ 7.0.*
7.1 unaffected ≤ *

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References
Link Providers
https://git.kernel.org/stable/c/7c89f474005d8377525d2991930b7432ee193a52 cve-icon
https://git.kernel.org/stable/c/9525e3a6fbb1d126a22ab2ee86ddea25af581a7c cve-icon
https://git.kernel.org/stable/c/b35a13036755c5803168a7cb93bc66035c3e65b8 cve-icon
https://lore.kernel.org/linux-cve-announce/2026071913-CVE-2026-64071-5a2d@gregkh/T cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2026-64071 cve-icon
https://www.cve.org/CVERecord?id=CVE-2026-64071 cve-icon
History

Mon, 20 Jul 2026 12:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-476
References
Metrics threat_severity

None

 cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Moderate

Sun, 19 Jul 2026 16:15:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: nvme-pci: fix use-after-free in nvme_free_host_mem() nvme_free_host_mem() frees dev->hmb_sgt via dma_free_noncontiguous() but never clears the pointer afterward. This leads to a use-after-free if nvme_free_host_mem() is called twice in the same error path. This can happen during nvme_probe() when nvme_setup_host_mem() succeeds in allocating the HMB (setting dev->hmb_sgt) but nvme_set_host_mem() fails with an I/O error: nvme_setup_host_mem() nvme_alloc_host_mem_single() -> sets dev->hmb_sgt nvme_set_host_mem() -> fails with -EIO nvme_free_host_mem() -> frees hmb_sgt, but does NOT NULL it return error nvme_probe() error path: nvme_free_host_mem() -> dev->hmb_sgt is stale, use-after-free The second call dereferences the freed sgt, causing a NULL pointer dereference in iommu_dma_free_noncontiguous() when it accesses sgt->sgl->dma_address (the backing memory has been freed and zeroed). This is reproducible on Thunderbolt-attached NVMe devices (e.g., OWC Envoy Express behind a Dell WD22TB4 dock) where the device intermittently returns I/O errors during HMB setup due to PCIe link instability. BUG: kernel NULL pointer dereference, address: 0000000000000010 RIP: 0010:iommu_dma_free_noncontiguous+0x22/0x80 Call Trace: <TASK> dma_free_noncontiguous+0x3b/0x130 nvme_free_host_mem+0x30/0xf0 [nvme] nvme_probe.cold+0xcc/0x275 [nvme] local_pci_probe+0x43/0xa0 pci_device_probe+0xeea/0x290 really_probe+0xf9/0x3b0 __driver_probe_device+0x8b/0x170 driver_probe_device+0x24/0xd0 __driver_attach_async_helper+0x6b/0x110 async_run_entry_fn+0x37/0x170 process_one_work+0x1ac/0x3d0 worker_thread+0x1b8/0x360 kthread+0xf7/0x130 ret_from_fork+0x2d8/0x3a0 ret_from_fork_asm+0x1a/0x30 </TASK> Fix this by setting dev->hmb_sgt to NULL after freeing it, so the second call takes the multi-descriptor path which safely handles the already-cleaned-up state.
Title nvme-pci: fix use-after-free in nvme_free_host_mem()
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-07-19T15:39:47.162Z

Reserved: 2026-07-19T07:54:57.031Z

Link: CVE-2026-64071

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-07-19T00:00:00Z

Links: CVE-2026-64071 - Bugzilla

cve-icon OpenCVE Enrichment

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Weaknesses