CVE-2026-64071
Estado: AnalizadaAlta (7.8)—
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:
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).
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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.
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.
Detalles técnicos trazas, registros y código del informe original
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
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>CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Puntuación base: 7.8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.13%
- Percentil entre todas las CVEs puntuadas: 2
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1068Exploitation for Privilege Escalationprivilege escalation85 % - Impacto principal
T1499.004Application or System Exploitationimpact75 %
Use-after-free (CWE-416) con acceso local privilegiado (PR:L) permite DoS mediante dereference de puntero nulo en nvme_free_host_mem(), causando kernel panic.
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (1)
CWE
- CWE-416
Referencias
JSON original (NVD)
Mostrar
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"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnvme-pci: fix use-after-free in nvme_free_host_mem()\n\nnvme_free_host_mem() frees dev->hmb_sgt via dma_free_noncontiguous()\nbut never clears the pointer afterward. This leads to a use-after-free\nif nvme_free_host_mem() is called twice in the same error path.\n\nThis can happen during nvme_probe() when nvme_setup_host_mem() succeeds\nin allocating the HMB (setting dev->hmb_sgt) but nvme_set_host_mem()\nfails with an I/O error:\n\n nvme_setup_host_mem()\n nvme_alloc_host_mem_single() -> sets dev->hmb_sgt\n nvme_set_host_mem() -> fails with -EIO\n nvme_free_host_mem() -> frees hmb_sgt, but does NOT NULL it\n return error\n\n nvme_probe() error path:\n nvme_free_host_mem() -> dev->hmb_sgt is stale, use-after-free\n\nThe second call dereferences the freed sgt, causing a NULL pointer\ndereference in iommu_dma_free_noncontiguous() when it accesses\nsgt->sgl->dma_address (the backing memory has been freed and zeroed).\n\nThis is reproducible on Thunderbolt-attached NVMe devices (e.g., OWC\nEnvoy Express behind a Dell WD22TB4 dock) where the device intermittently\nreturns I/O errors during HMB setup due to PCIe link instability.\n\n BUG: kernel NULL pointer dereference, address: 0000000000000010\n RIP: 0010:iommu_dma_free_noncontiguous+0x22/0x80\n Call Trace:\n <TASK>\n dma_free_noncontiguous+0x3b/0x130\n nvme_free_host_mem+0x30/0xf0 [nvme]\n nvme_probe.cold+0xcc/0x275 [nvme]\n local_pci_probe+0x43/0xa0\n pci_device_probe+0xeea/0x290\n really_probe+0xf9/0x3b0\n __driver_probe_device+0x8b/0x170\n driver_probe_device+0x24/0xd0\n __driver_attach_async_helper+0x6b/0x110\n async_run_entry_fn+0x37/0x170\n process_one_work+0x1ac/0x3d0\n worker_thread+0x1b8/0x360\n kthread+0xf7/0x130\n ret_from_fork+0x2d8/0x3a0\n ret_from_fork_asm+0x1a/0x30\n </TASK>\n\nFix this by setting dev->hmb_sgt to NULL after freeing it, so the\nsecond call takes the multi-descriptor path which safely handles the\nalready-cleaned-up state."
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"lastModified": "2026-09-03T14:54:13.197",
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