{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2026-97921", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-97921", "idYear": 2026, "status": "PUBLISHED", "publishedAt": "2026-09-25T10:22:41.081Z", "updatedAt": "2026-10-19T09:10:48.148Z", "importedAt": "2026-10-24T01:58:41.756Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "tracing: Free histogram the field rejected for a bad modifier", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Free histogram the field rejected for a bad modifier\n\nWriting a hist trigger whose value or variable carries a modifier that is\nnot allowed there leaks the fields that were built for it.\n\n__create_val_field() takes the field from parse_expr() and stores it in\nhist_data->fields[] only after the modifier checks have run:\n\n\thist_field = parse_expr(hist_data, file, field_str, flags, var_name,\n\t\t\t\t&n_subexprs);\n\t...\n\tif (hist_field->flags & HIST_FIELD_FL_VAR) {\n\t\tif (hist_field->flags & (...))\n\t\t\tgoto err;\n\t} else {\n\t\tif (hist_field->flags & (...))\n\t\t\tgoto err;\n\t}\n\n\thist_data->fields[val_idx] = hist_field;\n\nBoth checks jump past that store, and the err label returns without\nfreeing anything. The error unwinds to create_hist_data(), which calls\ndestroy_hist_data() -> destroy_hist_fields(), and that reaches a field\nonly by walking fields[]. A field that never got there is unreachable.\n\ncommit e0213434fe3e (\"tracing: Do not let histogram values have some\nmodifiers\") set ret to -EINVAL and fell through to the store, which left\nthe field owned by fields[] and freed along with the rest of hist_data.\nSplitting the check into a value case and a variable case replaced that\nfall-through with a goto that skips it.\n\nWith CONFIG_DEBUG_KMEMLEAK, 200 writes of\n\n # echo 'hist:keys=prev_pid:vals=next_pid.log2' > \\\n\t events/sched/sched_switch/trigger\n\neach correctly rejected with -EINVAL, leave 332 unreferenced objects\n(63744 bytes) reported at create_hist_field(); 200 install and remove\ncycles of a valid trigger leave none. A '.log2' field is two\nallocations, since create_hist_field() puts the plain field in\noperands[0] of the log2 field, and both are reported.\n\nUse destroy_hist_field() rather than __destroy_hist_field() so that\noperands[0] is freed as well. It returns early for HIST_FIELD_FL_VAR_REF,\nwhich is what an operand owned by hist_data->var_refs[] needs; the\nrejected field itself is never a var ref, because a var ref never carries\na modifier flag.", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "7403630eb94c1d664fb873f967427ef2f6ee3699", "status": "affected", "versionType": "git", "lessThan": "a2652fcf96b63e9da04951e4e58e6a0672df695d" }, { "version": "e30fbc618e97b38dbb49f1d44dcd0778d3f23b8c", "status": "affected", "versionType": "git", "lessThan": "3d42fed18b2c5707b6332ebe87b789fd768eb01b" }, { "version": "e30fbc618e97b38dbb49f1d44dcd0778d3f23b8c", "status": "affected", "versionType": "git", "lessThan": "e787361bb6b0026ea3eb4d3fa7a304c7fcb99555" }, { "version": "e30fbc618e97b38dbb49f1d44dcd0778d3f23b8c", "status": "affected", "versionType": "git", "lessThan": "b22dc0add7d72b8bd9cae3188db0dd65da1c8652" }, { "version": "e30fbc618e97b38dbb49f1d44dcd0778d3f23b8c", "status": "affected", "versionType": "git", "lessThan": "891c21f6d5673b2a519b536243bfc6dd2d35beb6" }, { "version": "e30fbc618e97b38dbb49f1d44dcd0778d3f23b8c", "status": "affected", "versionType": "git", "lessThan": "230234d12ce42ab04132a32c3a848f07a5d27a71" }, { "version": "8d505d06d7330f5d67d3e5e9e1c647fb0b10ddad", "status": "affected", "versionType": "git" }, { "version": "6.1.33", "status": "affected", "versionType": "semver", "lessThan": "6.1.189" }, { "version": "6.3.7", "status": "affected", "versionType": "semver", "lessThan": "6.4" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "6.4", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "6.4" }, { "version": "6.1.189", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.1.*" }, { "version": "6.6.158", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.6.*" }, { "version": "6.12.111", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.12.*" }, { "version": "6.18.53", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.18.*" }, { "version": "7.2.7", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "7.2.*" }, { "version": "7.3", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }