CVE-2026-97562

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-97562", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-24T16:01:01.155Z", "datePublished": "2026-09-25T10:21:50.664Z", "dateUpdated": "2026-10-19T09:09:25.220Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T09:09:25.220Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: pin DFS superblock in iterator callback\n\ntcon_super_cb() stores a raw superblock pointer, but __cifs_get_super()\ntakes its active reference only after iterate_supers_type() has dropped\ns_umount and its passive reference. Concurrent DFS automount expiry can\ntherefore free the superblock before cifs_sb_active() uses it.\n\nA deterministic KASAN test reproduces the race as:\n\n BUG: KASAN: slab-use-after-free in cifs_sb_active+0x77/0x80\n\nThe same test passes with this change applied.\n\nTake the active reference in the callback while iterate_supers_type()\nstill holds s_umount shared. cifs_put_tcp_super() remains the matching\nrelease."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H", "baseScore": 7.5, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:N - The racing side is started by the remote SMB server: dropping the session or replying STATUS_NETWORK_NAME_DELETED makes the client run smb2_reconnect() -> cifs_tree_connect() -> cifs_get_dfs_tcon_super() -> __cifs_get_super(). There, tcon_super_cb() saves a raw superblock pointer that is used after s_umount is released.\nAC:H - The server can force reconnects repeatedly, but the superblock is only freed if a DFS-link automount expires via cifs_expire_automounts() (a 500s periodic timer, idle submount only) inside the small gap between iterate_supers_type() returning and cifs_sb_active(). The attacker does not control that timing.\nPR:N - The attacker is the SMB/DFS server or a network peer that can reset the client's session. Forcing the client's tree reconnect needs no account or privilege on the client.\nUI:R - A victim must have mounted a DFS share with an automounted DFS link from the attacker-reachable server (cifs mounts need real CAP_SYS_ADMIN, not a user namespace), and the link must be idle long enough to expire.\nS:U - The use-after-free corrupts memory in the same kernel that runs the CIFS client, so no separate security authority is crossed.\nC:H - After the freed super_block and cifs_sb_info are reused, the reconnect path keeps reading them (cifs_sb_active() on freed memory, then CIFS_SB(sb) fields in tree_connect_dfs_target()), so reclaimed slab contents can be read.\nI:H - cifs_sb_active() increments counters in the freed cifs_sb/sb, and cifs_update_super_prepath() frees and replaces cifs_sb->prepath in the freed cifs_sb_info. Both are writes into freed memory that can be turned into heap corruption.\nA:H - The fix commit reports a KASAN slab-use-after-free in cifs_sb_active(); without KASAN the corrupted superblock refcounts and the later cifs_put_tcp_super()/deactivate_super() can crash the kernel."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/smb/client/misc.c"], "versions": [{"version": "bacd704a95ad0b93af995aae4a523aa046f46563", "lessThan": "3c9acc9835c304013a4faeb969fe9333d66ca9f8", "status": "affected", "versionType": "git"}, {"version": "bacd704a95ad0b93af995aae4a523aa046f46563", "lessThan": "ea43a15cea36dc5ddd832be5bddeac7dd804cbcf", "status": "affected", "versionType": "git"}, {"version": "bacd704a95ad0b93af995aae4a523aa046f46563", "lessThan": "a6b6561522212af852c9ad8a7dca8d59ef2c7377", "status": "affected", "versionType": "git"}, {"version": "bacd704a95ad0b93af995aae4a523aa046f46563", "lessThan": "5b01a8c0209690db75341528ec53fd87e0ac1460", "status": "affected", "versionType": "git"}, {"version": "bacd704a95ad0b93af995aae4a523aa046f46563", "lessThan": "d806d5a85dcbe2a0f181b2f0f9f61ddfbefa1818", "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/smb/client/misc.c"], "versions": [{"version": "5.7", "status": "affected"}, {"version": "0", "lessThan": "5.7", "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": "7.2.7", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.3", "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": "5.7", "versionEndExcluding": "6.6.158"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.7", "versionEndExcluding": "6.12.111"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.7", "versionEndExcluding": "6.18.53"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.7", "versionEndExcluding": "7.2.7"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.7", "versionEndExcluding": "7.3"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/3c9acc9835c304013a4faeb969fe9333d66ca9f8"}, {"url": "https://git.kernel.org/stable/c/ea43a15cea36dc5ddd832be5bddeac7dd804cbcf"}, {"url": "https://git.kernel.org/stable/c/a6b6561522212af852c9ad8a7dca8d59ef2c7377"}, {"url": "https://git.kernel.org/stable/c/5b01a8c0209690db75341528ec53fd87e0ac1460"}, {"url": "https://git.kernel.org/stable/c/d806d5a85dcbe2a0f181b2f0f9f61ddfbefa1818"}], "title": "smb: client: pin DFS superblock in iterator callback", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/smb/client/misc.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "3c9acc9835c304013a4faeb969fe9333d66ca9f8", "status": "affected", "version": "bacd704a95ad0b93af995aae4a523aa046f46563", "versionType": "git"}, {"lessThan": "ea43a15cea36dc5ddd832be5bddeac7dd804cbcf", "status": "affected", "version": "bacd704a95ad0b93af995aae4a523aa046f46563", "versionType": "git"}, {"lessThan": "a6b6561522212af852c9ad8a7dca8d59ef2c7377", "status": "affected", "version": "bacd704a95ad0b93af995aae4a523aa046f46563", "versionType": "git"}, {"lessThan": "5b01a8c0209690db75341528ec53fd87e0ac1460", "status": "affected", "version": "bacd704a95ad0b93af995aae4a523aa046f46563", "versionType": "git"}, {"lessThan": "d806d5a85dcbe2a0f181b2f0f9f61ddfbefa1818", "status": "affected", "version": "bacd704a95ad0b93af995aae4a523aa046f46563", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/smb/client/misc.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "5.7"}, {"lessThan": "5.7", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.158", "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": "7.2.*", "status": "unaffected", "version": "7.2.7", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3", "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\nsmb: client: pin DFS superblock in iterator callback\n\ntcon_super_cb() stores a raw superblock pointer, but __cifs_get_super()\ntakes its active reference only after iterate_supers_type() has dropped\ns_umount and its passive reference. Concurrent DFS automount expiry can\ntherefore free the superblock before cifs_sb_active() uses it.\n\nA deterministic KASAN test reproduces the race as:\n\n BUG: KASAN: slab-use-after-free in cifs_sb_active+0x77/0x80\n\nThe same test passes with this change applied.\n\nTake the active reference in the callback while iterate_supers_type()\nstill holds s_umount shared. cifs_put_tcp_super() remains the matching\nrelease."}], "id": "CVE-2026-97562", "lastModified": "2026-10-19T10:17:25.280", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.6, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-09-25T11:17:06.757", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/3c9acc9835c304013a4faeb969fe9333d66ca9f8"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/5b01a8c0209690db75341528ec53fd87e0ac1460"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/a6b6561522212af852c9ad8a7dca8d59ef2c7377"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/d806d5a85dcbe2a0f181b2f0f9f61ddfbefa1818"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/ea43a15cea36dc5ddd832be5bddeac7dd804cbcf"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: smb: client: pin DFS superblock in iterator callback", "id": "2541115", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2541115"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-911", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nsmb: client: pin DFS superblock in iterator callback\ntcon_super_cb() stores a raw superblock pointer, but __cifs_get_super()\ntakes its active reference only after iterate_supers_type() has dropped\ns_umount and its passive reference. Concurrent DFS automount expiry can\ntherefore free the superblock before cifs_sb_active() uses it.\nA deterministic KASAN test reproduces the race as:\nBUG: KASAN: slab-use-after-free in cifs_sb_active+0x77/0x80\nThe same test passes with this change applied.\nTake the active reference in the callback while iterate_supers_type()\nstill holds s_umount shared. cifs_put_tcp_super() remains the matching\nrelease.", "A flaw was found in the Linux kernel's SMB (Server Message Block) client. A race condition occurs when a Distributed File System (DFS) automount expires while the client processes active filesystem references, resulting in a use-after-free memory flaw. A local user could exploit this timing issue during automount operations to cause a system crash, resulting in a Denial of Service (DoS), or potentially execute arbitrary code."], "name": "CVE-2026-97562", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "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": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Fix deferred", "package_name": "openshift/ose-rhel-coreos-8", "product_name": "Red Hat OpenShift Container Platform 4"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Fix deferred", "package_name": "openshift/ose-rhel-coreos-9", "product_name": "Red Hat OpenShift Container Platform 4"}], "public_date": "2026-09-25T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-97562\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-97562\nhttps://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-97562.mbox"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[bacd704a95ad0b93af995aae4a523aa046f46563,ea43a15cea36dc5ddd832be5bddeac7dd804cbcf)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[bacd704a95ad0b93af995aae4a523aa046f46563,a6b6561522212af852c9ad8a7dca8d59ef2c7377)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[bacd704a95ad0b93af995aae4a523aa046f46563,5b01a8c0209690db75341528ec53fd87e0ac1460)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[bacd704a95ad0b93af995aae4a523aa046f46563,d806d5a85dcbe2a0f181b2f0f9f61ddfbefa1818)"}}], "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": "affected", "versions": {"scheme": "generic", "value": "5.7"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0.0.0,5.7.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.12.111,6.12.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.18.53,6.18.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2.7,7.2.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.3-rc3,*]"}}], "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": "2026-09-25T13:15:07.880840+00:00", "updated": "2026-10-01T09:30:05.896215+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"], "weaknesses": ["CWE-416", "CWE-911"]}