{"cve":"CVE-2026-46196","nvd":{"published":"2026-05-28T10:16:35.253","modified":"2026-10-15T02:19:50.060","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ntracepoint: balance regfunc() on func_add() failure in tracepoint_add_func()\n\nWhen a tracepoint goes through the 0 -> 1 transition, tracepoint_add_func()\ninvokes the subsystem's ext->regfunc() before attempting to install the\nnew probe via func_add(). If func_add() then fails (for example, when\nallocate_probes() cannot allocate a new probe array under memory pressure\nand returns -ENOMEM), the function returns the error without calling the\nmatching ext->unregfunc(), leaving the side effects of regfunc() behind\nwith no installed probe to justify them.\n\nFor syscall tracepoints this is particularly unpleasant: syscall_regfunc()\nbumps sys_tracepoint_refcount and sets SYSCALL_TRACEPOINT on every task.\nAfter a leaked failure, the refcount is stuck at a non-zero value with no\nconsumer, and every task continues paying the syscall trace entry/exit\noverhead until reboot. Other subsystems providing regfunc()/unregfunc()\npairs exhibit similarly scoped persistent state.\n\nMirror the existing 1 -> 0 cleanup and call ext->unregfunc() in the\nfunc_add() error path, gated on the same condition used there so the\nunwind is symmetric with the registration.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":[],"references":["https://git.kernel.org/stable/c/247ed8a969f981bfba3112fd4bb441eaa6cef59c","https://git.kernel.org/stable/c/2c5b8eeea006eb694c81631cd5713d494b80be90","https://git.kernel.org/stable/c/342829e042ac00f3d68d442ea92873fb6683f494","https://git.kernel.org/stable/c/36ff362235307af95152d510b53c2d9b8773a342","https://git.kernel.org/stable/c/4f1756d043e56ea2e9a6c858fb290a0cf6fc2251"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:36:28.938604137+00:00"},"epss":{"cve":"CVE-2026-46196","score":0.00134,"percentile":0.029,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}