{"id":"CVE-2026-64071","state":"PUBLISHED","title":"nvme-pci: fix use-after-free in nvme_free_host_mem()","description":"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.","publishedAt":"2026-07-19T15:39:47.162Z","updatedAt":"2026-07-19T15:39:47.162Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"63a5c7a4b4c49ad86c362e9f555e6f343804ee1d","status":"affected","lessThan":"9525e3a6fbb1d126a22ab2ee86ddea25af581a7c","versionType":"git"},{"version":"63a5c7a4b4c49ad86c362e9f555e6f343804ee1d","status":"affected","lessThan":"7c89f474005d8377525d2991930b7432ee193a52","versionType":"git"},{"version":"63a5c7a4b4c49ad86c362e9f555e6f343804ee1d","status":"affected","lessThan":"b35a13036755c5803168a7cb93bc66035c3e65b8","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/nvme/host/pci.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.13","versionType":"semver"},{"version":"6.18.34","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.11","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/nvme/host/pci.c"]}],"references":["https://git.kernel.org/stable/c/9525e3a6fbb1d126a22ab2ee86ddea25af581a7c","https://git.kernel.org/stable/c/7c89f474005d8377525d2991930b7432ee193a52","https://git.kernel.org/stable/c/b35a13036755c5803168a7cb93bc66035c3e65b8"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/64xxx/CVE-2026-64071.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64071","state":"PUBLISHED","datePublished":"2026-07-19T15:39:47.162Z","dateUpdated":"2026-07-19T15:39:47.162Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T07:54:57.031Z"},"containers":{"cna":{"title":"nvme-pci: fix use-after-free in nvme_free_host_mem()","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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"63a5c7a4b4c49ad86c362e9f555e6f343804ee1d","status":"affected","lessThan":"9525e3a6fbb1d126a22ab2ee86ddea25af581a7c","versionType":"git"},{"version":"63a5c7a4b4c49ad86c362e9f555e6f343804ee1d","status":"affected","lessThan":"7c89f474005d8377525d2991930b7432ee193a52","versionType":"git"},{"version":"63a5c7a4b4c49ad86c362e9f555e6f343804ee1d","status":"affected","lessThan":"b35a13036755c5803168a7cb93bc66035c3e65b8","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/nvme/host/pci.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.13","versionType":"semver"},{"version":"6.18.34","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.11","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/nvme/host/pci.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/9525e3a6fbb1d126a22ab2ee86ddea25af581a7c"},{"url":"https://git.kernel.org/stable/c/7c89f474005d8377525d2991930b7432ee193a52"},{"url":"https://git.kernel.org/stable/c/b35a13036755c5803168a7cb93bc66035c3e65b8"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-07-19T15:39:47.162Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"6.18.34"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"7.0.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}