{"api_version":"1","generated_at":"2026-06-26T12:32:13+00:00","cve":"CVE-2026-53271","urls":{"html":"https://cve.report/CVE-2026-53271","api":"https://cve.report/api/cve/CVE-2026-53271.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-53271","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-53271"},"summary":{"title":"ksmbd: fix NULL-deref of opinfo->conn in oplock/lease break notifiers","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix NULL-deref of opinfo->conn in oplock/lease break notifiers\n\nsmb2_oplock_break_noti() and smb2_lease_break_noti() read opinfo->conn\ninto a local with neither READ_ONCE() nor a NULL check.  Both run from\noplock_break() after opinfo_get_list() has dropped ci->m_lock, so a\nconcurrent SMB2 LOGOFF (session_fd_check()) can set op->conn = NULL\nunder ci->m_lock within that window.  ksmbd_conn_r_count_inc(conn) then\nwrites through NULL at offset 0xc4 -- a remotely triggerable oops.\n\nGuard both reads the way compare_guid_key() already does: read\nopinfo->conn with READ_ONCE() and return early if it is NULL, before\nallocating the work struct so nothing leaks.  A NULL conn means the\nclient is gone and the break is moot, so return 0; oplock_break() treats\nthat as success and runs the normal teardown.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-06-25 09:16:45","updated_at":"2026-06-25 09:16:45"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/1ff58dcfcab434ebb51649da33774fbb8e1f7b67","name":"https://git.kernel.org/stable/c/1ff58dcfcab434ebb51649da33774fbb8e1f7b67","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/b003086d76968298f22e7cf62239833b5a3a06b1","name":"https://git.kernel.org/stable/c/b003086d76968298f22e7cf62239833b5a3a06b1","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/e735dbd489e3ea02be78dba991056fe1138be51e","name":"https://git.kernel.org/stable/c/e735dbd489e3ea02be78dba991056fe1138be51e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/75e33deda658c1ab3a9336cbdb1436536f9b3660","name":"https://git.kernel.org/stable/c/75e33deda658c1ab3a9336cbdb1436536f9b3660","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/945a86b21b40fb17183f5b27461baa6f03e2467f","name":"https://git.kernel.org/stable/c/945a86b21b40fb17183f5b27461baa6f03e2467f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-53271","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53271","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 8df4bcdb0a4232192b2445256c39b787d58ef14d 945a86b21b40fb17183f5b27461baa6f03e2467f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected c8efcc786146a951091588e5fa7e3c754850cb3c 1ff58dcfcab434ebb51649da33774fbb8e1f7b67 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected c8efcc786146a951091588e5fa7e3c754850cb3c e735dbd489e3ea02be78dba991056fe1138be51e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected c8efcc786146a951091588e5fa7e3c754850cb3c 75e33deda658c1ab3a9336cbdb1436536f9b3660 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected c8efcc786146a951091588e5fa7e3c754850cb3c b003086d76968298f22e7cf62239833b5a3a06b1 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.6.32 6.6.143 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.9","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.9 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.143 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.94 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.36 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0.13 7.0.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"53271","cve":"CVE-2026-53271","epss":"0.001640000","percentile":"0.058950000","score_date":"2026-06-25","updated_at":"2026-06-26 00:06:14"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/smb/server/oplock.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"945a86b21b40fb17183f5b27461baa6f03e2467f","status":"affected","version":"8df4bcdb0a4232192b2445256c39b787d58ef14d","versionType":"git"},{"lessThan":"1ff58dcfcab434ebb51649da33774fbb8e1f7b67","status":"affected","version":"c8efcc786146a951091588e5fa7e3c754850cb3c","versionType":"git"},{"lessThan":"e735dbd489e3ea02be78dba991056fe1138be51e","status":"affected","version":"c8efcc786146a951091588e5fa7e3c754850cb3c","versionType":"git"},{"lessThan":"75e33deda658c1ab3a9336cbdb1436536f9b3660","status":"affected","version":"c8efcc786146a951091588e5fa7e3c754850cb3c","versionType":"git"},{"lessThan":"b003086d76968298f22e7cf62239833b5a3a06b1","status":"affected","version":"c8efcc786146a951091588e5fa7e3c754850cb3c","versionType":"git"},{"lessThan":"6.6.143","status":"affected","version":"6.6.32","versionType":"semver"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/smb/server/oplock.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":"6.6.*","status":"unaffected","version":"6.6.143","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.94","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.36","versionType":"semver"},{"lessThanOrEqual":"7.0.*","status":"unaffected","version":"7.0.13","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.143","versionStartIncluding":"6.6.32","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.94","versionStartIncluding":"6.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.36","versionStartIncluding":"6.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0.13","versionStartIncluding":"6.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1","versionStartIncluding":"6.9","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix NULL-deref of opinfo->conn in oplock/lease break notifiers\n\nsmb2_oplock_break_noti() and smb2_lease_break_noti() read opinfo->conn\ninto a local with neither READ_ONCE() nor a NULL check.  Both run from\noplock_break() after opinfo_get_list() has dropped ci->m_lock, so a\nconcurrent SMB2 LOGOFF (session_fd_check()) can set op->conn = NULL\nunder ci->m_lock within that window.  ksmbd_conn_r_count_inc(conn) then\nwrites through NULL at offset 0xc4 -- a remotely triggerable oops.\n\nGuard both reads the way compare_guid_key() already does: read\nopinfo->conn with READ_ONCE() and return early if it is NULL, before\nallocating the work struct so nothing leaks.  A NULL conn means the\nclient is gone and the break is moot, so return 0; oplock_break() treats\nthat as success and runs the normal teardown."}],"providerMetadata":{"dateUpdated":"2026-06-25T08:39:56.489Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/945a86b21b40fb17183f5b27461baa6f03e2467f"},{"url":"https://git.kernel.org/stable/c/1ff58dcfcab434ebb51649da33774fbb8e1f7b67"},{"url":"https://git.kernel.org/stable/c/e735dbd489e3ea02be78dba991056fe1138be51e"},{"url":"https://git.kernel.org/stable/c/75e33deda658c1ab3a9336cbdb1436536f9b3660"},{"url":"https://git.kernel.org/stable/c/b003086d76968298f22e7cf62239833b5a3a06b1"}],"title":"ksmbd: fix NULL-deref of opinfo->conn in oplock/lease break notifiers","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-53271","datePublished":"2026-06-25T08:39:56.489Z","dateReserved":"2026-06-09T07:44:35.395Z","dateUpdated":"2026-06-25T08:39:56.489Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-06-25 09:16:45","lastModifiedDate":"2026-06-25 09:16:45","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"53271","Ordinal":"1","Title":"ksmbd: fix NULL-deref of opinfo->conn in oplock/lease break noti","CVE":"CVE-2026-53271","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"53271","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix NULL-deref of opinfo->conn in oplock/lease break notifiers\n\nsmb2_oplock_break_noti() and smb2_lease_break_noti() read opinfo->conn\ninto a local with neither READ_ONCE() nor a NULL check.  Both run from\noplock_break() after opinfo_get_list() has dropped ci->m_lock, so a\nconcurrent SMB2 LOGOFF (session_fd_check()) can set op->conn = NULL\nunder ci->m_lock within that window.  ksmbd_conn_r_count_inc(conn) then\nwrites through NULL at offset 0xc4 -- a remotely triggerable oops.\n\nGuard both reads the way compare_guid_key() already does: read\nopinfo->conn with READ_ONCE() and return early if it is NULL, before\nallocating the work struct so nothing leaks.  A NULL conn means the\nclient is gone and the break is moot, so return 0; oplock_break() treats\nthat as success and runs the normal teardown.","Type":"Description","Title":"ksmbd: fix NULL-deref of opinfo->conn in oplock/lease break noti"}]}}}