{"id":"CVE-2026-90066","summary":"samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nsamples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify\n\nftrace_direct_multi_init() assigns kthread_run()'s return value to\nsimple_tsk without an IS_ERR() check. When kthread_run() fails it\nreturns ERR_PTR(-ENOMEM), but init still returns 0, so the module loads\nwith simple_tsk holding an error pointer. On unload,\nftrace_direct_multi_exit() then passes that ERR_PTR to kthread_stop(),\nleading to a null-pointer-dereference.\n\nCheck the return value of kthread_run() with IS_ERR(); on failure,\nunregister the ftrace direct call and propagate the error code.","modified":"2026-09-19T03:47:23.830395459Z","published":"2026-09-17T16:05:48.921Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90066.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/626614df9080d7052fbe24dc90b5434717ab7a9f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6727b7618f49401acf373fa3ec5712e2ec52e5cf"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7a96b9f6d5ba23dbce66c8a4a242effd4c01a830"},{"type":"WEB","url":"https://git.kernel.org/stable/c/98b7b2a29ae87937aa02ab9391543ef8c602cd94"},{"type":"WEB","url":"https://git.kernel.org/stable/c/cf839636911d8313f3ecd098329fd0b96499e4cf"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90066.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-90066"},{"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":"e1067a07cfbc5a36abad3752fafe4c79e06db1bb"},{"fixed":"7a96b9f6d5ba23dbce66c8a4a242effd4c01a830"},{"fixed":"98b7b2a29ae87937aa02ab9391543ef8c602cd94"},{"fixed":"626614df9080d7052fbe24dc90b5434717ab7a9f"},{"fixed":"cf839636911d8313f3ecd098329fd0b96499e4cf"},{"fixed":"6727b7618f49401acf373fa3ec5712e2ec52e5cf"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90066.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.6.157"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.110"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.52"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90066.json"}}],"schema_version":"1.9.0"}