{"id":"CVE-2026-89630","revision":"1adbd190734c4bdab770b79ed0b1fe5c","records":[{"revision":"1adbd190734c4bdab770b79ed0b1fe5c","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-89630","aliases":[],"title":"smb: client: restore the data_offset bound in is_valid_oplock_break()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: restore the data_offset bound in is_valid_oplock_break()\n\nCommit 83bfbd0bb902 (\"cifs: Remove the RFC1002 header from smb_hdr\")\nchanged the quantity this bound is measured against.  It used to be\nsrv->total_read minus the 4-byte RFC1002 preamble that total_read then\nincluded, so it was the SMB message length.  The same commit stopped\ncounting the preamble, and the mechanical substitution to\nsrv->total_read - srv->pdu_size left an expression that is identically\nzero: standard_receive3() reads MID_HEADER_SIZE() bytes and then exactly\npdu_length - MID_HEADER_SIZE() more, adding both to total_read.\n\nlen is therefore 0, the subtraction below it wraps, and no __u32\nDataOffset can exceed the result, so the check from commit 097f5863b1a0\n(\"cifs: read overflow in is_valid_oplock_break()\") no longer rejects\nanything.  Use total_read, which is now the message length on its own.","state":0,"publishedAt":"2026-09-11T19:45:25.697+00:00","modifiedAt":"2026-10-19T08:50:02.437+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"fs/smb/client/smb1misc.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"83bfbd0bb9025f98fa62b44f93bd67466773d1db\",\n                            \"lessThan\": \"5b16a1967a01ad4496a7206a87c3eb16f1df2b05\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"83bfbd0bb9025f98fa62b44f93bd67466773d1db\",\n                            \"lessThan\": \"ba22f575de9deeae4ae0859ca4315a7698226237\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"78e718c5aa146063cd70d2cc68297c3ac41f31ee\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"6.18.56\",\n                            \"lessThan\": \"6.19\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"fs/smb/client/smb1misc.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.19\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.19\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.4\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","score":9.1,"severity":"CRITICAL"}],"references":["https://git.kernel.org/stable/c/5b16a1967a01ad4496a7206a87c3eb16f1df2b05","https://git.kernel.org/stable/c/ba22f575de9deeae4ae0859ca4315a7698226237"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89630","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-89630","identifiers":["CVE-2026-89630"]},"retained":false,"historicalAffected":[]}],"coverage":[]}