{"id":"CVE-2026-97923","title":"In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Free histogram the var ref when its initialization fails\n\ncreate_var_ref() allocates a VAR_REF hist_field and then calls\ninit_var_ref() to fill it in","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Free histogram the var ref when its initialization fails\n\ncreate_var_ref() allocates a VAR_REF hist_field and then calls\ninit_var_ref() to fill it in. When tha…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-772"],"vendor":"Linux","product":"Linux","affected":["Linux >= 656fe2ba85e81d00e4447bf77b8da2be3c47acb2 < 608b7751926ec08fae6a1ac4e7308195da68c362","Linux >= 656fe2ba85e81d00e4447bf77b8da2be3c47acb2 < 4870f9071c9ea3c1423a07741b85a794db30d672","Linux >= 656fe2ba85e81d00e4447bf77b8da2be3c47acb2 < 352f84a381e7b4651b30366e93cb858f3fa9c91a","Linux >= 656fe2ba85e81d00e4447bf77b8da2be3c47acb2 < 4924328d6991f25b65bb7c8ff5d56c2a9b254851","Linux >= 656fe2ba85e81d00e4447bf77b8da2be3c47acb2 < 74375caa20fe5165807b4334c783d1790b01f02a","Linux >= 656fe2ba85e81d00e4447bf77b8da2be3c47acb2 < 222abcbe7866fef04563b6eb89fb21f627dcbc77","Linux >= 656fe2ba85e81d00e4447bf77b8da2be3c47acb2 < a69baeac38677270656e85753d93856a076dee57","Linux >= 656fe2ba85e81d00e4447bf77b8da2be3c47acb2 < 516001d53e6b2ea95a251ee2ef54a1a689a3fd58","Linux 836717841a30d7845cdf9cb806ee0ff3bfa7135a","Linux >= 4.19.100 < 4.20","Linux 5.0"],"published":"2026-09-25","updated":"2026-10-03","sourceUpdated":"2026-10-03T11:18:10.060","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-97923","references":[{"url":"https://git.kernel.org/stable/c/222abcbe7866fef04563b6eb89fb21f627dcbc77","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/352f84a381e7b4651b30366e93cb858f3fa9c91a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4870f9071c9ea3c1423a07741b85a794db30d672","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4924328d6991f25b65bb7c8ff5d56c2a9b254851","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/516001d53e6b2ea95a251ee2ef54a1a689a3fd58","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/608b7751926ec08fae6a1ac4e7308195da68c362","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/74375caa20fe5165807b4334c783d1790b01f02a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a69baeac38677270656e85753d93856a076dee57","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-97923.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-97923"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2541180"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-97923"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-97923"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-97923.mbox"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"epss":0.00211,"epssPercentile":0.11208,"cvssSource":"vendor","ingestedAt":"2026-09-25T11:06:38.888Z","slug":"CVE-2026-97923","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Free histogram the var ref when its initialization fails\n\ncreate_var_ref() allocates a VAR_REF hist_field and then calls\ninit_var_ref() to fill it in. When that fails the field is leaked.\n\ncommit 656fe2ba85e8 (\"tracing: Use hist trigger's var_ref array to destroy\nvar_refs\") made destroy_hist_field() return early for\nHIST_FIELD_FL_VAR_REF, since var refs are freed by walking the trigger's\nvar_refs[] array instead. create_var_ref() adds the field to that array\nonly after init_var_ref() has succeeded, so on this path the field is in\nneither place and nothing frees it. The call was correct when it was\nwritten, before var refs were taken out of destroy_hist_field().\n\ninit_var_ref() cannot free it either. The caller owns the field, so\ninit_var_ref() undoes only its own string allocations and leaves the\nfield alone. Freeing it there would leave create_var_ref() passing freed\nmemory to destroy_hist_field(), which reads its flags.\n\nCall __destroy_hist_field(), which frees the field without consulting\nthe flag.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-09-29 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-97923.json)","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":213461,"id":"CVE-2026-97923","ts":1790754733247,"field":"cvss","old":null,"new":"5.5"},{"seq":213460,"id":"CVE-2026-97923","ts":1790754733247,"field":"severity","old":"none","new":"medium"}]}