CVE-2026-93827

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-93827", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-18T17:59:28.792Z", "datePublished": "2026-09-24T16:03:05.795Z", "dateUpdated": "2026-09-25T12:43:36.887Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-09-25T12:43:36.887Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvirtio-fs: avoid double-free on failed queue setup\n\nvirtio_fs_setup_vqs() allocates fs->vqs and fs->mq_map before calling\nvirtio_find_vqs(). If virtio_find_vqs() fails, the error path frees both\npointers and returns an error to virtio_fs_probe().\n\nvirtio_fs_probe() then drops the last kobject reference, and\nvirtio_fs_ktype_release() frees fs->vqs and fs->mq_map again. This leaves\ndangling pointers in struct virtio_fs and can trigger a double-free during\nprobe failure cleanup.\n\nSet fs->vqs and fs->mq_map to NULL immediately after kfree() in the\nvirtio_fs_setup_vqs() error path so that the later kobject release sees an\nuninitialized state and kfree(NULL) becomes harmless.\n\nThis can be reproduced when a broken virtio-fs device advertises more\nrequest queues than the transport actually provides. In that case\nvirtio_find_vqs() fails while setting up the extra queue, and the probe\npath reaches the double-free cleanup sequence."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.4, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:L - The triggering field is virtio_fs_config.num_request_queues, read by virtio_cread_le() in virtio_fs_setup_vqs() from virtio_fs_probe() via virtio_dev_probe() after virtio_pci_probe()/register_virtio_device() binds a VIRTIO_ID_FS device; those bytes come from local PCI/MMIO/vDPA config space, not a network protocol message.\nAC:L - A device that advertises more request queues than it exposes makes virtio_find_vqs()->vp_setup_vq() fail (-EINVAL when index >= vp_modern_get_num_queues(), or -ENOENT on queue size 0); virtio_fs_setup_vqs() then kfree's fs->vqs and fs->mq_map and virtio_fs_probe() always kobject_put()s into the second free, with no race.\nPR:N - virtio_fs_probe()/virtio_fs_setup_vqs() have no capable() or credential check; MODULE_DEVICE_TABLE(virtio, id_table) autoloads virtiofs and virtio_dev_probe() binds a VIRTIO_ID_FS device at enumeration or hotplug, so a malicious virtio-fs backend needs no account on the guest.\nUI:N - The double-free runs in the probe error path (virtio_fs_setup_vqs() failure, then kobject_put() into virtio_fs_ktype_release()) when the device appears; virtio_fs_add_instance() and a virtiofs mount are never reached, so no victim must mount or open anything.\nS:U - virtio_fs_ktype_release() double-frees the guest kernel kmalloc objects fs->vqs and fs->mq_map; that is device-to-guest heap corruption inside the same guest kernel, not a write into host virtiofsd or a KVM/IOMMU escape.\nC:H - kfree(fs->vqs) and kfree(fs->mq_map) in virtio_fs_setup_vqs() leave dangling pointers that virtio_fs_ktype_release() frees again; a slab double-free of that virtio_fs_vq array and per-CPU mq_map lets those objects overlap so the attacker can read adjacent kernel heap.\nI:H - The same second kfree of fs->vqs and fs->mq_map corrupts the SLUB freelist for those kmalloc objects and is an arbitrary-free primitive, enabling heap overwrite and control-flow hijack in the guest kernel.\nA:H - Double-free of fs->vqs and fs->mq_map in virtio_fs_ktype_release() after virtio_find_vqs() fails oopses or panics the guest during probe cleanup (KASAN invalid-free, SLUB poisoned-freelist BUG, or panic_on_oops)."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/fuse/virtio_fs.c"], "versions": [{"version": "a8f62f50b4e4ea92a938fca2ec1bd108d7f210e9", "lessThan": "3fbc5ee776fefbc6ea34d2518f1f5f90aa2e1dad", "status": "affected", "versionType": "git"}, {"version": "a8f62f50b4e4ea92a938fca2ec1bd108d7f210e9", "lessThan": "20ef4739b329bb09cff11dd2458795a50674658e", "status": "affected", "versionType": "git"}, {"version": "a8f62f50b4e4ea92a938fca2ec1bd108d7f210e9", "lessThan": "6af3330ec5d5fb8c06c04eb520a71cf73ea5a765", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/fuse/virtio_fs.c"], "versions": [{"version": "6.9", "status": "affected"}, {"version": "0", "lessThan": "6.9", "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": "6.9", "versionEndExcluding": "6.12.111"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "6.18.53"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "7.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/3fbc5ee776fefbc6ea34d2518f1f5f90aa2e1dad"}, {"url": "https://git.kernel.org/stable/c/20ef4739b329bb09cff11dd2458795a50674658e"}, {"url": "https://git.kernel.org/stable/c/6af3330ec5d5fb8c06c04eb520a71cf73ea5a765"}], "title": "virtio-fs: avoid double-free on failed queue setup", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/fuse/virtio_fs.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "3fbc5ee776fefbc6ea34d2518f1f5f90aa2e1dad", "status": "affected", "version": "a8f62f50b4e4ea92a938fca2ec1bd108d7f210e9", "versionType": "git"}, {"lessThan": "20ef4739b329bb09cff11dd2458795a50674658e", "status": "affected", "version": "a8f62f50b4e4ea92a938fca2ec1bd108d7f210e9", "versionType": "git"}, {"lessThan": "6af3330ec5d5fb8c06c04eb520a71cf73ea5a765", "status": "affected", "version": "a8f62f50b4e4ea92a938fca2ec1bd108d7f210e9", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/fuse/virtio_fs.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.9"}, {"lessThan": "6.9", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.111", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.53", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvirtio-fs: avoid double-free on failed queue setup\n\nvirtio_fs_setup_vqs() allocates fs->vqs and fs->mq_map before calling\nvirtio_find_vqs(). If virtio_find_vqs() fails, the error path frees both\npointers and returns an error to virtio_fs_probe().\n\nvirtio_fs_probe() then drops the last kobject reference, and\nvirtio_fs_ktype_release() frees fs->vqs and fs->mq_map again. This leaves\ndangling pointers in struct virtio_fs and can trigger a double-free during\nprobe failure cleanup.\n\nSet fs->vqs and fs->mq_map to NULL immediately after kfree() in the\nvirtio_fs_setup_vqs() error path so that the later kobject release sees an\nuninitialized state and kfree(NULL) becomes harmless.\n\nThis can be reproduced when a broken virtio-fs device advertises more\nrequest queues than the transport actually provides. In that case\nvirtio_find_vqs() fails while setting up the extra queue, and the probe\npath reaches the double-free cleanup sequence."}], "id": "CVE-2026-93827", "lastModified": "2026-09-25T13:17:23.513", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 8.4, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 2.5, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-09-24T17:17:16.410", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/20ef4739b329bb09cff11dd2458795a50674658e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/3fbc5ee776fefbc6ea34d2518f1f5f90aa2e1dad"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/6af3330ec5d5fb8c06c04eb520a71cf73ea5a765"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: virtio-fs: avoid double-free on failed queue setup", "id": "2540396", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2540396"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.0", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-1341", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nvirtio-fs: avoid double-free on failed queue setup\nvirtio_fs_setup_vqs() allocates fs->vqs and fs->mq_map before calling\nvirtio_find_vqs(). If virtio_find_vqs() fails, the error path frees both\npointers and returns an error to virtio_fs_probe().\nvirtio_fs_probe() then drops the last kobject reference, and\nvirtio_fs_ktype_release() frees fs->vqs and fs->mq_map again. This leaves\ndangling pointers in struct virtio_fs and can trigger a double-free during\nprobe failure cleanup.\nSet fs->vqs and fs->mq_map to NULL immediately after kfree() in the\nvirtio_fs_setup_vqs() error path so that the later kobject release sees an\nuninitialized state and kfree(NULL) becomes harmless.\nThis can be reproduced when a broken virtio-fs device advertises more\nrequest queues than the transport actually provides. In that case\nvirtio_find_vqs() fails while setting up the extra queue, and the probe\npath reaches the double-free cleanup sequence.", "A flaw was found in the Linux kernel's virtio-fs file system driver. When queue initialization fails\u2014such as when a device advertises more request queues than supported\u2014the driver fails to clear memory pointers after releasing them, resulting in a double-free condition during error cleanup. An attacker capable of presenting a malformed virtio-fs device can exploit this flaw to cause memory corruption, leading to a system crash and Denial of Service (DoS)."], "name": "CVE-2026-93827", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Not affected", "package_name": "openshift/ose-rhel-coreos-8", "product_name": "Red Hat OpenShift Container Platform 4"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Affected", "package_name": "openshift/ose-rhel-coreos-9", "product_name": "Red Hat OpenShift Container Platform 4"}], "public_date": "2026-09-24T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-93827\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-93827\nhttps://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-93827.mbox"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,3fbc5ee776fefbc6ea34d2518f1f5f90aa2e1dad)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,20ef4739b329bb09cff11dd2458795a50674658e)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,6af3330ec5d5fb8c06c04eb520a71cf73ea5a765)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,6.12.111)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,6.18.53)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.111,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.53,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-09-24T23:30:17.305562+00:00", "updated": "2026-10-01T17:15:10.308779+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"], "weaknesses": ["CWE-1341", "CWE-416"]}