{"api_version":"1","generated_at":"2026-10-04T05:27:28+00:00","cve":"CVE-2026-97556","urls":{"html":"https://cve.report/CVE-2026-97556","api":"https://cve.report/api/cve/CVE-2026-97556.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-97556","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-97556"},"summary":{"title":"smb: client: avoid leaking refcount when cifs_sb_tlink() fails","description":"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.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-25 11:17:06","updated_at":"2026-10-03 11:18:03"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/9ec991e148368e3207e98134c509a625097f7693","name":"https://git.kernel.org/stable/c/9ec991e148368e3207e98134c509a625097f7693","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/e9c5bcc88b8337157e480c85a6d2f326bc265012","name":"https://git.kernel.org/stable/c/e9c5bcc88b8337157e480c85a6d2f326bc265012","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/dd03fd658ea59821505e0e643b6b7cbdf51c4e1d","name":"https://git.kernel.org/stable/c/dd03fd658ea59821505e0e643b6b7cbdf51c4e1d","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/1d1b0f1d812a4011a57bc6c70492c34a2e46c6dd","name":"https://git.kernel.org/stable/c/1d1b0f1d812a4011a57bc6c70492c34a2e46c6dd","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/23b26f4408ac3f35a482d2e5cf6fc865d4201b71","name":"https://git.kernel.org/stable/c/23b26f4408ac3f35a482d2e5cf6fc865d4201b71","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/55c5f095d4df14271b238f826e1392fda7b6e60e","name":"https://git.kernel.org/stable/c/55c5f095d4df14271b238f826e1392fda7b6e60e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-97556","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-97556","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5ee28bcfbaacf289eb25c662a2862542ea6ce6a7 55c5f095d4df14271b238f826e1392fda7b6e60e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected e8f5f849ffce24490eb9449e98312b66c0dba76f e9c5bcc88b8337157e480c85a6d2f326bc265012 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected e8f5f849ffce24490eb9449e98312b66c0dba76f 9ec991e148368e3207e98134c509a625097f7693 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected e8f5f849ffce24490eb9449e98312b66c0dba76f dd03fd658ea59821505e0e643b6b7cbdf51c4e1d git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected e8f5f849ffce24490eb9449e98312b66c0dba76f 1d1b0f1d812a4011a57bc6c70492c34a2e46c6dd git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected e8f5f849ffce24490eb9449e98312b66c0dba76f 23b26f4408ac3f35a482d2e5cf6fc865d4201b71 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected b99f490ea87ebcca3a429fd8837067feb56a4c7c git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6b67a6d2e50634fe127e656147c81915955e9f5e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.1.47 6.1.189 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.15.128 5.16 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.4.12 6.5 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.5","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.5 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.189 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.158 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.111 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.53 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.7 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc3 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"97556","cve":"CVE-2026-97556","epss":"0.002000000","percentile":"0.089010000","score_date":"2026-10-03","updated_at":"2026-10-04 00:03:16"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"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":"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":"b99f490ea87ebcca3a429fd8837067feb56a4c7c","versionType":"git"},{"status":"affected","version":"6b67a6d2e50634fe127e656147c81915955e9f5e","versionType":"git"},{"lessThan":"6.1.189","status":"affected","version":"6.1.47","versionType":"semver"},{"lessThan":"5.16","status":"affected","version":"5.15.128","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":"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-rc3","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.189","versionStartIncluding":"6.1.47","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.158","versionStartIncluding":"6.5","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.111","versionStartIncluding":"6.5","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.53","versionStartIncluding":"6.5","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.7","versionStartIncluding":"6.5","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc3","versionStartIncluding":"6.5","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15.128","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.4.12","vulnerable":true}],"negate":false,"operator":"OR"}]}],"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."}],"providerMetadata":{"dateUpdated":"2026-10-03T10:59:36.845Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"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"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-97556","datePublished":"2026-09-25T10:21:47.078Z","dateReserved":"2026-09-24T16:01:01.154Z","dateUpdated":"2026-10-03T10:59:36.845Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-25 11:17:06","lastModifiedDate":"2026-10-03 11:18:03","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"97556","Ordinal":"1","Title":"smb: client: avoid leaking refcount when cifs_sb_tlink() fails","CVE":"CVE-2026-97556","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"97556","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"smb: client: avoid leaking refcount when cifs_sb_tlink() fails"}]}}}