{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-93782", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-18T17:59:28.788Z", "datePublished": "2026-09-24T16:02:14.457Z", "dateUpdated": "2026-10-03T10:57:16.951Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-03T10:57:16.951Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvhost-scsi: flush backend after device ioctls\n\nvhost-scsi translates guest response descriptors into userspace iovecs\nwhen commands are submitted. Target-core completes those commands\nasynchronously, so VHOST_SET_MEM_TABLE can replace the memory table while\nan in-flight command still retains response iovecs translated through the\nold table.\n\nIf the old mapping is reused after VHOST_SET_MEM_TABLE returns, command\ncompletion can write the response to an unrelated userspace object.\n\nFlush the vhost-scsi backend after vhost_dev_ioctl() handles a device\nioctl. This waits for in-flight commands that can still use the old\nresponse iovecs before the ioctl returns." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The missing flush is in vhost_scsi_ioctl() after vhost_dev_ioctl() handles VHOST_SET_MEM_TABLE via vhost_set_memory() on /dev/vhost-scsi; the retained pointers are tvc_resp_iovs filled by vhost_scsi_setup_resp_iovs() from vhost_get_vq_desc() on the local virtio-scsi virtqueue, not a network PDU.\nAC:H - A guest can leave commands in target-core via vhost_scsi_handle_vq()->vhost_scsi_target_queue_cmd()->target_submit(), but cannot call VHOST_SET_MEM_TABLE; only the VMM issues that ioctl (memory hotplug or live migration), so the replacement that makes old HVAs reusable is outside the attacker's control.\nPR:L - The attacker is a VM tenant sending virtio-scsi I/O that plants those tvc_resp_iovs; vhost_scsi_open() and vhost_scsi_ioctl() have no capable() check, and the already-attached LIO tpg (VHOST_SCSI_SET_ENDPOINT by QEMU) lets that guest I/O run without host root.\nUI:N - The guest plants in-flight commands by kicking its own virtqueue; no other user must mount an image or open a file. A later VMM VHOST_SET_MEM_TABLE is ordinary hypervisor memory-listener bookkeeping, not a tricked interactive action.\nS:C - vhost_scsi_complete_cmd_work() copy_to_iter()s virtio_scsi_cmd_resp through stale tvc_resp_iovs (and vhost_scsi_copy_sgl_to_iov() through a stale read_iter) into the host QEMU mm, so guest-originated completion corrupts VMM userspace across the KVM guest-to-host boundary.\nC:H - After QEMU reuses the old HVA, completion writes into unrelated VMM objects; the copied_iov READ path (vhost_scsi_copy_iov_to_sgl() dup_iter, then vhost_scsi_copy_sgl_to_iov()) can copy LUN data into that remapped heap, which is leverageable to disclose host memory back to the guest.\nI:H - copy_to_iter() of the packed virtio_scsi_cmd_resp plus, when vhost_scsi_map_to_sgl() falls back to vhost_scsi_copy_iov_to_sgl() for misaligned I/O with sgl_count>BIO_MAX_VECS, a guest-influenced READ payload into the remapped HVA, corrupting QEMU heap objects and enabling VMM control-flow hijack.\nA:H - A reused QEMU mapping hit by that completion write corrupts VMM heap metadata and aborts QEMU, terminating the VM; an unmapped old HVA only hits the \"Faulted on virtio_scsi_cmd_resp\" path, but reuse after VHOST_SET_MEM_TABLE is the contract the ioctl was supposed to guarantee." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/vhost/scsi.c" ], "versions": [ { "version": "057cbf49a1f08297877e46c82f707b1bfea806a8", "lessThan": "6436411203d8c702ffc055700f1a6bde488ff681", "status": "affected", "versionType": "git" }, { "version": "057cbf49a1f08297877e46c82f707b1bfea806a8", "lessThan": "cec088285adcc7ae23c119b6bbdb22270dc2de8f", "status": "affected", "versionType": "git" }, { "version": "057cbf49a1f08297877e46c82f707b1bfea806a8", "lessThan": "e0bf6bed528693a6b32439ab122b34a34b66d96f", "status": "affected", "versionType": "git" }, { "version": "057cbf49a1f08297877e46c82f707b1bfea806a8", "lessThan": "be2636e1b21fe860db918152abf2932638d06ed7", "status": "affected", "versionType": "git" }, { "version": "057cbf49a1f08297877e46c82f707b1bfea806a8", "lessThan": "981c97d09c6b9560bb12dcc41f11ce59b1a48e97", "status": "affected", "versionType": "git" }, { "version": "057cbf49a1f08297877e46c82f707b1bfea806a8", "lessThan": "6c1b802e36b05ebd9d41686c4dce6f06966af469", "status": "affected", "versionType": "git" }, { "version": "057cbf49a1f08297877e46c82f707b1bfea806a8", "lessThan": "22598f55a4c2b510b3df5e69e563387a963222ae", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/vhost/scsi.c" ], "versions": [ { "version": "3.6", "status": "affected" }, { "version": "0", "lessThan": "3.6", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.271", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.222", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.189", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.158", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.111", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.53", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.6", "versionEndExcluding": "5.10.271" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.6", "versionEndExcluding": "5.15.222" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.6", "versionEndExcluding": "6.1.189" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.6", "versionEndExcluding": "6.6.158" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.6", "versionEndExcluding": "6.12.111" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.6", "versionEndExcluding": "6.18.53" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.6", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/6436411203d8c702ffc055700f1a6bde488ff681" }, { "url": "https://git.kernel.org/stable/c/cec088285adcc7ae23c119b6bbdb22270dc2de8f" }, { "url": "https://git.kernel.org/stable/c/e0bf6bed528693a6b32439ab122b34a34b66d96f" }, { "url": "https://git.kernel.org/stable/c/be2636e1b21fe860db918152abf2932638d06ed7" }, { "url": "https://git.kernel.org/stable/c/981c97d09c6b9560bb12dcc41f11ce59b1a48e97" }, { "url": "https://git.kernel.org/stable/c/6c1b802e36b05ebd9d41686c4dce6f06966af469" }, { "url": "https://git.kernel.org/stable/c/22598f55a4c2b510b3df5e69e563387a963222ae" } ], "title": "vhost-scsi: flush backend after device ioctls", "x_generator": { "engine": "bippy-1.2.0" } } } }