CVE-2026-97556

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-97556", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-24T16:01:01.154Z", "datePublished": "2026-09-25T10:21:47.078Z", "dateUpdated": "2026-10-30T12:37:21.053Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-30T12:37:21.053Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: avoid leaking refcount when cifs_sb_tlink() fails\n\ncifs_oplock_break() takes over the reference that\ncifs_queue_oplock_break() acquired when it queued the work, and drops it\nwith _cifsFileInfo_put() once the break has been processed.\n\nOnly in setups with \"-o multiuser\", cifs_sb_tlink() may fail, at which\npoint cifs_oplock_break() returns without putting the file reference,\nmirroring the reference leak we already fixed in the companion patch to\ncifs_queue_oplock_break().\n\nThis would trigger a crash due to busy inodes on the next unmount:\n\n BUG: Dentry ... still in use (1) [unmount of cifs cifs]\n VFS: Busy inodes after unmount of cifs (cifs)\n\nDrop the reference on that path as well. Doing so before the out label\nmirrors the normal path, which also puts the reference before\ncifs_done_oplock_break().\n\nFound by Sashiko code review. The failure path was not exercised at\nruntime."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/smb/client/file.c"], "versions": [{"version": "b99f490ea87ebcca3a429fd8837067feb56a4c7c", "lessThan": "f1fd8a84181b3af03c508e0b02b4877945dd070a", "status": "affected", "versionType": "git"}, {"version": "5ee28bcfbaacf289eb25c662a2862542ea6ce6a7", "lessThan": "55c5f095d4df14271b238f826e1392fda7b6e60e", "status": "affected", "versionType": "git"}, {"version": "e8f5f849ffce24490eb9449e98312b66c0dba76f", "lessThan": "e9c5bcc88b8337157e480c85a6d2f326bc265012", "status": "affected", "versionType": "git"}, {"version": "e8f5f849ffce24490eb9449e98312b66c0dba76f", "lessThan": "9ec991e148368e3207e98134c509a625097f7693", "status": "affected", "versionType": "git"}, {"version": "e8f5f849ffce24490eb9449e98312b66c0dba76f", "lessThan": "dd03fd658ea59821505e0e643b6b7cbdf51c4e1d", "status": "affected", "versionType": "git"}, {"version": "e8f5f849ffce24490eb9449e98312b66c0dba76f", "lessThan": "1d1b0f1d812a4011a57bc6c70492c34a2e46c6dd", "status": "affected", "versionType": "git"}, {"version": "e8f5f849ffce24490eb9449e98312b66c0dba76f", "lessThan": "23b26f4408ac3f35a482d2e5cf6fc865d4201b71", "status": "affected", "versionType": "git"}, {"version": "6b67a6d2e50634fe127e656147c81915955e9f5e", "status": "affected", "versionType": "git"}, {"version": "5.15.128", "lessThan": "5.15.224", "status": "affected", "versionType": "semver"}, {"version": "6.1.47", "lessThan": "6.1.189", "status": "affected", "versionType": "semver"}, {"version": "6.4.12", "lessThan": "6.5", "status": "affected", "versionType": "semver"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/smb/client/file.c"], "versions": [{"version": "6.5", "status": "affected"}, {"version": "0", "lessThan": "6.5", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.224", "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": "7.2.7", "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": "5.15.128", "versionEndExcluding": "5.15.224"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1.47", "versionEndExcluding": "6.1.189"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.5", "versionEndExcluding": "6.6.158"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.5", "versionEndExcluding": "6.12.111"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.5", "versionEndExcluding": "6.18.53"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.5", "versionEndExcluding": "7.2.7"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.5", "versionEndExcluding": "7.3"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4.12"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/f1fd8a84181b3af03c508e0b02b4877945dd070a"}, {"url": "https://git.kernel.org/stable/c/55c5f095d4df14271b238f826e1392fda7b6e60e"}, {"url": "https://git.kernel.org/stable/c/e9c5bcc88b8337157e480c85a6d2f326bc265012"}, {"url": "https://git.kernel.org/stable/c/9ec991e148368e3207e98134c509a625097f7693"}, {"url": "https://git.kernel.org/stable/c/dd03fd658ea59821505e0e643b6b7cbdf51c4e1d"}, {"url": "https://git.kernel.org/stable/c/1d1b0f1d812a4011a57bc6c70492c34a2e46c6dd"}, {"url": "https://git.kernel.org/stable/c/23b26f4408ac3f35a482d2e5cf6fc865d4201b71"}], "title": "smb: client: avoid leaking refcount when cifs_sb_tlink() fails", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/smb/client/file.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "f1fd8a84181b3af03c508e0b02b4877945dd070a", "status": "affected", "version": "b99f490ea87ebcca3a429fd8837067feb56a4c7c", "versionType": "git"}, {"lessThan": "55c5f095d4df14271b238f826e1392fda7b6e60e", "status": "affected", "version": "5ee28bcfbaacf289eb25c662a2862542ea6ce6a7", "versionType": "git"}, {"lessThan": "e9c5bcc88b8337157e480c85a6d2f326bc265012", "status": "affected", "version": "e8f5f849ffce24490eb9449e98312b66c0dba76f", "versionType": "git"}, {"lessThan": "9ec991e148368e3207e98134c509a625097f7693", "status": "affected", "version": "e8f5f849ffce24490eb9449e98312b66c0dba76f", "versionType": "git"}, {"lessThan": "dd03fd658ea59821505e0e643b6b7cbdf51c4e1d", "status": "affected", "version": "e8f5f849ffce24490eb9449e98312b66c0dba76f", "versionType": "git"}, {"lessThan": "1d1b0f1d812a4011a57bc6c70492c34a2e46c6dd", "status": "affected", "version": "e8f5f849ffce24490eb9449e98312b66c0dba76f", "versionType": "git"}, {"lessThan": "23b26f4408ac3f35a482d2e5cf6fc865d4201b71", "status": "affected", "version": "e8f5f849ffce24490eb9449e98312b66c0dba76f", "versionType": "git"}, {"status": "affected", "version": "6b67a6d2e50634fe127e656147c81915955e9f5e", "versionType": "git"}, {"lessThan": "5.15.224", "status": "affected", "version": "5.15.128", "versionType": "semver"}, {"lessThan": "6.1.189", "status": "affected", "version": "6.1.47", "versionType": "semver"}, {"lessThan": "6.5", "status": "affected", "version": "6.4.12", "versionType": "semver"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/smb/client/file.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.5"}, {"lessThan": "6.5", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "5.15.*", "status": "unaffected", "version": "5.15.224", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.189", "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: avoid leaking refcount when cifs_sb_tlink() fails\n\ncifs_oplock_break() takes over the reference that\ncifs_queue_oplock_break() acquired when it queued the work, and drops it\nwith _cifsFileInfo_put() once the break has been processed.\n\nOnly in setups with \"-o multiuser\", cifs_sb_tlink() may fail, at which\npoint cifs_oplock_break() returns without putting the file reference,\nmirroring the reference leak we already fixed in the companion patch to\ncifs_queue_oplock_break().\n\nThis would trigger a crash due to busy inodes on the next unmount:\n\n BUG: Dentry ... still in use (1) [unmount of cifs cifs]\n VFS: Busy inodes after unmount of cifs (cifs)\n\nDrop the reference on that path as well. Doing so before the out label\nmirrors the normal path, which also puts the reference before\ncifs_done_oplock_break().\n\nFound by Sashiko code review. The failure path was not exercised at\nruntime."}], "id": "CVE-2026-97556", "lastModified": "2026-10-30T13:21:07.670", "metrics": {}, "published": "2026-09-25T11:17:06.077", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/1d1b0f1d812a4011a57bc6c70492c34a2e46c6dd"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/23b26f4408ac3f35a482d2e5cf6fc865d4201b71"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/55c5f095d4df14271b238f826e1392fda7b6e60e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/9ec991e148368e3207e98134c509a625097f7693"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/dd03fd658ea59821505e0e643b6b7cbdf51c4e1d"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/e9c5bcc88b8337157e480c85a6d2f326bc265012"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/f1fd8a84181b3af03c508e0b02b4877945dd070a"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: smb: client: avoid leaking refcount when cifs_sb_tlink() fails", "id": "2541159", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2541159"}, "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: avoid leaking refcount when cifs_sb_tlink() fails\ncifs_oplock_break() takes over the reference that\ncifs_queue_oplock_break() acquired when it queued the work, and drops it\nwith _cifsFileInfo_put() once the break has been processed.\nOnly in setups with \"-o multiuser\", cifs_sb_tlink() may fail, at which\npoint cifs_oplock_break() returns without putting the file reference,\nmirroring the reference leak we already fixed in the companion patch to\ncifs_queue_oplock_break().\nThis would trigger a crash due to busy inodes on the next unmount:\nBUG: Dentry ... still in use (1) [unmount of cifs cifs]\nVFS: Busy inodes after unmount of cifs (cifs)\nDrop the reference on that path as well. Doing so before the out label\nmirrors the normal path, which also puts the reference before\ncifs_done_oplock_break().\nFound by Sashiko code review. The failure path was not exercised at\nruntime.", "A flaw was found in the Linux kernel's SMB client. This vulnerability can lead to a denial of service (DoS) on systems using multi-user CIFS mount configurations. When processing an opportunistic lock (oplock) break, an error during tree link lookup prevents the client from releasing an acquired file reference count. A local user can trigger this condition, leaving filesystem resources marked as busy and causing the kernel to crash when the filesystem is unmounted."], "name": "CVE-2026-97556", "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": "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": "Fix deferred", "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": "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-2026-97556\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-97556\nhttps://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-97556.mbox"], "threat_severity": "Low"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[e8f5f849ffce24490eb9449e98312b66c0dba76f,9ec991e148368e3207e98134c509a625097f7693)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[e8f5f849ffce24490eb9449e98312b66c0dba76f,dd03fd658ea59821505e0e643b6b7cbdf51c4e1d)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[e8f5f849ffce24490eb9449e98312b66c0dba76f,1d1b0f1d812a4011a57bc6c70492c34a2e46c6dd)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[e8f5f849ffce24490eb9449e98312b66c0dba76f,23b26f4408ac3f35a482d2e5cf6fc865d4201b71)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "b99f490ea87ebcca3a429fd8837067feb56a4c7c"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[5.15.128,5.16)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[6.1.47,6.2)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[6.4.12,6.5)"}}], "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": "semver", "value": "6.5"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,6.5)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.111,7.0.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.53,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.2.7,7.3.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,*]"}}], "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": "2026-09-25T17:15:14.755922+00:00", "updated": "2026-10-01T12:15:05.362742+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}