nvme-pci: fix use-after-free in nvme_free_host_mem()
Summary
| CVE | CVE-2026-64071 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-07-19 16:17:47 UTC |
| Updated | 2026-07-19 16:17:47 UTC |
| 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. |
Risk And Classification
EPSS: 0.001730000 probability, percentile 0.070140000 (date 2026-07-20)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 63a5c7a4b4c49ad86c362e9f555e6f343804ee1d 9525e3a6fbb1d126a22ab2ee86ddea25af581a7c git | Not specified |
| CNA | Linux | Linux | affected 63a5c7a4b4c49ad86c362e9f555e6f343804ee1d 7c89f474005d8377525d2991930b7432ee193a52 git | Not specified |
| CNA | Linux | Linux | affected 63a5c7a4b4c49ad86c362e9f555e6f343804ee1d b35a13036755c5803168a7cb93bc66035c3e65b8 git | Not specified |
| CNA | Linux | Linux | affected 6.13 | Not specified |
| CNA | Linux | Linux | unaffected 6.13 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.34 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.0.11 7.0.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.1 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/9525e3a6fbb1d126a22ab2ee86ddea25af581a7c | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/b35a13036755c5803168a7cb93bc66035c3e65b8 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/7c89f474005d8377525d2991930b7432ee193a52 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.