{"id":"CVE-2026-97923","state":"PUBLISHED","title":"tracing: Free histogram the var ref when its initialization fails","description":"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 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.","publishedAt":"2026-09-25T10:22:42.300Z","updatedAt":"2026-10-19T09:10:50.106Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"656fe2ba85e81d00e4447bf77b8da2be3c47acb2","status":"affected","lessThan":"608b7751926ec08fae6a1ac4e7308195da68c362","versionType":"git"},{"version":"656fe2ba85e81d00e4447bf77b8da2be3c47acb2","status":"affected","lessThan":"4870f9071c9ea3c1423a07741b85a794db30d672","versionType":"git"},{"version":"656fe2ba85e81d00e4447bf77b8da2be3c47acb2","status":"affected","lessThan":"352f84a381e7b4651b30366e93cb858f3fa9c91a","versionType":"git"},{"version":"656fe2ba85e81d00e4447bf77b8da2be3c47acb2","status":"affected","lessThan":"4924328d6991f25b65bb7c8ff5d56c2a9b254851","versionType":"git"},{"version":"656fe2ba85e81d00e4447bf77b8da2be3c47acb2","status":"affected","lessThan":"74375caa20fe5165807b4334c783d1790b01f02a","versionType":"git"},{"version":"656fe2ba85e81d00e4447bf77b8da2be3c47acb2","status":"affected","lessThan":"222abcbe7866fef04563b6eb89fb21f627dcbc77","versionType":"git"},{"version":"656fe2ba85e81d00e4447bf77b8da2be3c47acb2","status":"affected","lessThan":"a69baeac38677270656e85753d93856a076dee57","versionType":"git"},{"version":"656fe2ba85e81d00e4447bf77b8da2be3c47acb2","status":"affected","lessThan":"516001d53e6b2ea95a251ee2ef54a1a689a3fd58","versionType":"git"},{"version":"836717841a30d7845cdf9cb806ee0ff3bfa7135a","status":"affected","versionType":"git"},{"version":"4.19.100","status":"affected","lessThan":"4.20","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/trace/trace_events_hist.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.0","versionType":"semver"},{"version":"5.10.271","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.222","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.189","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.158","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.111","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.53","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.7","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/trace/trace_events_hist.c"]}],"references":["https://git.kernel.org/stable/c/608b7751926ec08fae6a1ac4e7308195da68c362","https://git.kernel.org/stable/c/4870f9071c9ea3c1423a07741b85a794db30d672","https://git.kernel.org/stable/c/352f84a381e7b4651b30366e93cb858f3fa9c91a","https://git.kernel.org/stable/c/4924328d6991f25b65bb7c8ff5d56c2a9b254851","https://git.kernel.org/stable/c/74375caa20fe5165807b4334c783d1790b01f02a","https://git.kernel.org/stable/c/222abcbe7866fef04563b6eb89fb21f627dcbc77","https://git.kernel.org/stable/c/a69baeac38677270656e85753d93856a076dee57","https://git.kernel.org/stable/c/516001d53e6b2ea95a251ee2ef54a1a689a3fd58"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/97xxx/CVE-2026-97923.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-97923","state":"PUBLISHED","datePublished":"2026-09-25T10:22:42.300Z","dateUpdated":"2026-10-19T09:10:50.106Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:18:58.202Z"},"containers":{"cna":{"title":"tracing: Free histogram the var ref when its initialization fails","descriptions":[{"lang":"en","value":"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 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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"656fe2ba85e81d00e4447bf77b8da2be3c47acb2","status":"affected","lessThan":"608b7751926ec08fae6a1ac4e7308195da68c362","versionType":"git"},{"version":"656fe2ba85e81d00e4447bf77b8da2be3c47acb2","status":"affected","lessThan":"4870f9071c9ea3c1423a07741b85a794db30d672","versionType":"git"},{"version":"656fe2ba85e81d00e4447bf77b8da2be3c47acb2","status":"affected","lessThan":"352f84a381e7b4651b30366e93cb858f3fa9c91a","versionType":"git"},{"version":"656fe2ba85e81d00e4447bf77b8da2be3c47acb2","status":"affected","lessThan":"4924328d6991f25b65bb7c8ff5d56c2a9b254851","versionType":"git"},{"version":"656fe2ba85e81d00e4447bf77b8da2be3c47acb2","status":"affected","lessThan":"74375caa20fe5165807b4334c783d1790b01f02a","versionType":"git"},{"version":"656fe2ba85e81d00e4447bf77b8da2be3c47acb2","status":"affected","lessThan":"222abcbe7866fef04563b6eb89fb21f627dcbc77","versionType":"git"},{"version":"656fe2ba85e81d00e4447bf77b8da2be3c47acb2","status":"affected","lessThan":"a69baeac38677270656e85753d93856a076dee57","versionType":"git"},{"version":"656fe2ba85e81d00e4447bf77b8da2be3c47acb2","status":"affected","lessThan":"516001d53e6b2ea95a251ee2ef54a1a689a3fd58","versionType":"git"},{"version":"836717841a30d7845cdf9cb806ee0ff3bfa7135a","status":"affected","versionType":"git"},{"version":"4.19.100","status":"affected","lessThan":"4.20","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/trace/trace_events_hist.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.0","versionType":"semver"},{"version":"5.10.271","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.222","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.189","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.158","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.111","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.53","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.7","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/trace/trace_events_hist.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/608b7751926ec08fae6a1ac4e7308195da68c362"},{"url":"https://git.kernel.org/stable/c/4870f9071c9ea3c1423a07741b85a794db30d672"},{"url":"https://git.kernel.org/stable/c/352f84a381e7b4651b30366e93cb858f3fa9c91a"},{"url":"https://git.kernel.org/stable/c/4924328d6991f25b65bb7c8ff5d56c2a9b254851"},{"url":"https://git.kernel.org/stable/c/74375caa20fe5165807b4334c783d1790b01f02a"},{"url":"https://git.kernel.org/stable/c/222abcbe7866fef04563b6eb89fb21f627dcbc77"},{"url":"https://git.kernel.org/stable/c/a69baeac38677270656e85753d93856a076dee57"},{"url":"https://git.kernel.org/stable/c/516001d53e6b2ea95a251ee2ef54a1a689a3fd58"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T09:10:50.106Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"5.10.271"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"5.15.222"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"6.1.189"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"6.6.158"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"6.12.111"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"6.18.53"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"7.2.7"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"7.3"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.19.100"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}