CVE-2026-64071
Full vulnerability record from the local CVENow database.
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.
View original CVE JSON
{
"id": "CVE-2026-64071",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-07-19T16:17:47.687",
"lastModified": "2026-11-06T17:18:35.980",
"vulnStatus": "Analyzed",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"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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{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
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"defaultStatus": "unaffected",
"programFiles": [
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],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
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"metrics": {
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"source": "[email protected]",
"type": "Primary",
"cvssData": {
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"baseScore": 7.8,
"baseSeverity": "HIGH",
"attackVector": "LOCAL",
"attackComplexity": "LOW",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"availabilityImpact": "HIGH"
},
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}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-11-06T16:29:42.686574Z",
"id": "CVE-2026-64071",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
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{
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"role": "CISA Coordinator",
"version": "2.0.3"
}
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"weaknesses": [
{
"source": "[email protected]",
"type": "Primary",
"description": [
{
"lang": "en",
"value": "CWE-416"
}
]
}
],
"configurations": [
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"negate": false,
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