CVE-2026-97921

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-97921", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:18:58.202Z", "datePublished": "2026-09-25T10:22:41.081Z", "dateUpdated": "2026-10-19T09:10:48.148Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T09:10:48.148Z"}, "descriptions": [{"lang": "en", "value": "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": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["kernel/trace/trace_events_hist.c"], "versions": [{"version": "7403630eb94c1d664fb873f967427ef2f6ee3699", "lessThan": "a2652fcf96b63e9da04951e4e58e6a0672df695d", "status": "affected", "versionType": "git"}, {"version": "e30fbc618e97b38dbb49f1d44dcd0778d3f23b8c", "lessThan": "3d42fed18b2c5707b6332ebe87b789fd768eb01b", "status": "affected", "versionType": "git"}, {"version": "e30fbc618e97b38dbb49f1d44dcd0778d3f23b8c", "lessThan": "e787361bb6b0026ea3eb4d3fa7a304c7fcb99555", "status": "affected", "versionType": "git"}, {"version": "e30fbc618e97b38dbb49f1d44dcd0778d3f23b8c", "lessThan": "b22dc0add7d72b8bd9cae3188db0dd65da1c8652", "status": "affected", "versionType": "git"}, {"version": "e30fbc618e97b38dbb49f1d44dcd0778d3f23b8c", "lessThan": "891c21f6d5673b2a519b536243bfc6dd2d35beb6", "status": "affected", "versionType": "git"}, {"version": "e30fbc618e97b38dbb49f1d44dcd0778d3f23b8c", "lessThan": "230234d12ce42ab04132a32c3a848f07a5d27a71", "status": "affected", "versionType": "git"}, {"version": "8d505d06d7330f5d67d3e5e9e1c647fb0b10ddad", "status": "affected", "versionType": "git"}, {"version": "6.1.33", "lessThan": "6.1.189", "status": "affected", "versionType": "semver"}, {"version": "6.3.7", "lessThan": "6.4", "status": "affected", "versionType": "semver"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["kernel/trace/trace_events_hist.c"], "versions": [{"version": "6.4", "status": "affected"}, {"version": "0", "lessThan": "6.4", "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": "6.1.33", "versionEndExcluding": "6.1.189"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "6.6.158"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "6.12.111"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "6.18.53"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "7.2.7"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "7.3"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.3.7"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/a2652fcf96b63e9da04951e4e58e6a0672df695d"}, {"url": "https://git.kernel.org/stable/c/3d42fed18b2c5707b6332ebe87b789fd768eb01b"}, {"url": "https://git.kernel.org/stable/c/e787361bb6b0026ea3eb4d3fa7a304c7fcb99555"}, {"url": "https://git.kernel.org/stable/c/b22dc0add7d72b8bd9cae3188db0dd65da1c8652"}, {"url": "https://git.kernel.org/stable/c/891c21f6d5673b2a519b536243bfc6dd2d35beb6"}, {"url": "https://git.kernel.org/stable/c/230234d12ce42ab04132a32c3a848f07a5d27a71"}], "title": "tracing: Free histogram the field rejected for a bad modifier", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["kernel/trace/trace_events_hist.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "a2652fcf96b63e9da04951e4e58e6a0672df695d", "status": "affected", "version": "7403630eb94c1d664fb873f967427ef2f6ee3699", "versionType": "git"}, {"lessThan": "3d42fed18b2c5707b6332ebe87b789fd768eb01b", "status": "affected", "version": "e30fbc618e97b38dbb49f1d44dcd0778d3f23b8c", "versionType": "git"}, {"lessThan": "e787361bb6b0026ea3eb4d3fa7a304c7fcb99555", "status": "affected", "version": "e30fbc618e97b38dbb49f1d44dcd0778d3f23b8c", "versionType": "git"}, {"lessThan": "b22dc0add7d72b8bd9cae3188db0dd65da1c8652", "status": "affected", "version": "e30fbc618e97b38dbb49f1d44dcd0778d3f23b8c", "versionType": "git"}, {"lessThan": "891c21f6d5673b2a519b536243bfc6dd2d35beb6", "status": "affected", "version": "e30fbc618e97b38dbb49f1d44dcd0778d3f23b8c", "versionType": "git"}, {"lessThan": "230234d12ce42ab04132a32c3a848f07a5d27a71", "status": "affected", "version": "e30fbc618e97b38dbb49f1d44dcd0778d3f23b8c", "versionType": "git"}, {"status": "affected", "version": "8d505d06d7330f5d67d3e5e9e1c647fb0b10ddad", "versionType": "git"}, {"lessThan": "6.1.189", "status": "affected", "version": "6.1.33", "versionType": "semver"}, {"lessThan": "6.4", "status": "affected", "version": "6.3.7", "versionType": "semver"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["kernel/trace/trace_events_hist.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.4"}, {"lessThan": "6.4", "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", "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\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."}], "id": "CVE-2026-97921", "lastModified": "2026-10-19T10:17:42.817", "metrics": {}, "published": "2026-09-25T11:17:19.160", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/230234d12ce42ab04132a32c3a848f07a5d27a71"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/3d42fed18b2c5707b6332ebe87b789fd768eb01b"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/891c21f6d5673b2a519b536243bfc6dd2d35beb6"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/a2652fcf96b63e9da04951e4e58e6a0672df695d"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/b22dc0add7d72b8bd9cae3188db0dd65da1c8652"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/e787361bb6b0026ea3eb4d3fa7a304c7fcb99555"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: tracing: Free histogram the field rejected for a bad modifier", "id": "2541310", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2541310"}, "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-772", "details": ["In the Linux kernel, the following vulnerability has been resolved:\ntracing: Free histogram the field rejected for a bad modifier\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__create_val_field() takes the field from parse_expr() and stores it in\nhist_data->fields[] only after the modifier checks have run:\nhist_field = parse_expr(hist_data, file, field_str, flags, var_name,\n&n_subexprs);\n...\nif (hist_field->flags & HIST_FIELD_FL_VAR) {\nif (hist_field->flags & (...))\ngoto err;\n} else {\nif (hist_field->flags & (...))\ngoto err;\n}\nhist_data->fields[val_idx] = hist_field;\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.\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.\nWith CONFIG_DEBUG_KMEMLEAK, 200 writes of\n# echo 'hist:keys=prev_pid:vals=next_pid.log2' > \\\nevents/sched/sched_switch/trigger\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.\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.", "A flaw was found in the Linux kernel's tracing subsystem. When configuring event histogram triggers, specifying an unpermitted modifier for a value or variable fails to release previously allocated memory on error. A local user with tracing access can exploit this flaw by repeatedly submitting invalid triggers, leading to a memory leak and a potential Denial of Service (DoS) due to kernel memory exhaustion."], "name": "CVE-2026-97921", "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": "Not affected", "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": "Not affected", "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-2026-97921\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-97921\nhttps://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-97921.mbox"], "threat_severity": "Low"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[e30fbc618e97b38dbb49f1d44dcd0778d3f23b8c,e787361bb6b0026ea3eb4d3fa7a304c7fcb99555)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[e30fbc618e97b38dbb49f1d44dcd0778d3f23b8c,b22dc0add7d72b8bd9cae3188db0dd65da1c8652)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[e30fbc618e97b38dbb49f1d44dcd0778d3f23b8c,891c21f6d5673b2a519b536243bfc6dd2d35beb6)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[e30fbc618e97b38dbb49f1d44dcd0778d3f23b8c,230234d12ce42ab04132a32c3a848f07a5d27a71)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[7403630eb94c1d664fb873f967427ef2f6ee3699,*]"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[8d505d06d7330f5d67d3e5e9e1c647fb0b10ddad,*]"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[6.1.33,6.2)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[6.3.7,6.4)"}}], "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": "6.4"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,6.4)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.12.111,6.12.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.18.53,6.18.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2.7,7.2.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.3-rc3,*]"}}], "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": "2026-09-25T19:45:17.526085+00:00", "updated": "2026-10-01T05:45:17.049791+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"], "weaknesses": ["CWE-401", "CWE-772"]}