{"id":"CVE-2026-64028","summary":"tracing: Avoid NULL return from hist_field_name() on truncation","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Avoid NULL return from hist_field_name() on truncation\n\nhist_field_name() returns \"\" everywhere except the fully-qualified\nVAR_REF/EXPR case, where snprintf() truncation returns NULL early\nand bypasses the bottom NULL-\u003e\"\" guard. Callers don't expect NULL:\nstrcat(expr, hist_field_name(field, 0)) at trace_events_hist.c:1758\nand the strcmp() in the sort-key match loop at :4804 both deref it.\n\nsystem and event_name are bounded by MAX_EVENT_NAME_LEN, but the\nfield name on a VAR_REF is kstrdup'd from a histogram variable\nname parsed out of the trigger string and has no length cap, so\na long enough var name in a fully qualified reference can reach\nthe truncation path.\n\nKeep the length check but leave field_name as \"\" on overflow.","modified":"2026-07-21T03:47:51.911821635Z","published":"2026-07-19T15:39:19.102Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64028.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0402a1d3ddec565132867337ed44514a09d84728"},{"type":"WEB","url":"https://git.kernel.org/stable/c/37377b39ff86dacbc533275c1155210d4fd5dc91"},{"type":"WEB","url":"https://git.kernel.org/stable/c/576ec047d20b368b43c4d5db98c4f2e0f3c101ec"},{"type":"WEB","url":"https://git.kernel.org/stable/c/915c1254fe0788abddc31095b360e9dc98907a34"},{"type":"WEB","url":"https://git.kernel.org/stable/c/be4e99038c1603fa6b329d8ee3e364825e17c353"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d6c8b3ebdcdb12b59ad4212acb137cc56cae453d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e3f5d42cdc2f167719564693675f1eead81378ea"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e91687643c440ca3997d67646e6f80b92edc6703"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64028.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64028"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"2e8578364061c4e88ae33bc20c2d6f64f365f6a2"},{"fixed":"e3f5d42cdc2f167719564693675f1eead81378ea"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"dfd1cd57ee6067301841b7b0967c70f910a51150"},{"fixed":"37377b39ff86dacbc533275c1155210d4fd5dc91"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"e5c223f46c2e0691461dd97510c15e1f77148872"},{"fixed":"0402a1d3ddec565132867337ed44514a09d84728"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"9399a92989354e34086f9a5c379493217df83c5e"},{"fixed":"e91687643c440ca3997d67646e6f80b92edc6703"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"3cb6cb9c5a547a1979ad74f38eefe8e3687d96e0"},{"fixed":"be4e99038c1603fa6b329d8ee3e364825e17c353"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"0402c60abe769098d77f3b3bd1e29a97922b614b"},{"fixed":"d6c8b3ebdcdb12b59ad4212acb137cc56cae453d"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"6929e650db8451a9975ac0a631ba2d6e5d1e80ba"},{"fixed":"915c1254fe0788abddc31095b360e9dc98907a34"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"5ec1d1e97de134beed3a5b08235a60fc1c51af96"},{"fixed":"576ec047d20b368b43c4d5db98c4f2e0f3c101ec"}]}],"versions":["v6.6.141","v6.12.91","v6.18.33","v7.0.10"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64028.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.6.141"},{"fixed":"6.6.142"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.12.91"},{"fixed":"6.12.92"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.18.33"},{"fixed":"6.18.34"}]},{"type":"ECOSYSTEM","events":[{"introduced":"7.0.10"},{"fixed":"7.0.11"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64028.json"}}],"schema_version":"1.7.5"}