{"cve":"CVE-2025-40341","nvd":{"published":"2025-12-09T16:17:44.387","modified":"2026-10-14T21:10:00.183","status":"Deferred","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nfutex: Don't leak robust_list pointer on exec race\n\nsys_get_robust_list() and compat_get_robust_list() use ptrace_may_access()\nto check if the calling task is allowed to access another task's\nrobust_list pointer. This check is racy against a concurrent exec() in the\ntarget process.\n\nDuring exec(), a task may transition from a non-privileged binary to a\nprivileged one (e.g., setuid binary) and its credentials/memory mappings\nmay change. If get_robust_list() performs ptrace_may_access() before\nthis transition, it may erroneously allow access to sensitive information\nafter the target becomes privileged.\n\nA racy access allows an attacker to exploit a window during which\nptrace_may_access() passes before a target process transitions to a\nprivileged state via exec().\n\nFor example, consider a non-privileged task T that is about to execute a\nsetuid-root binary. An attacker task A calls get_robust_list(T) while T\nis still unprivileged. Since ptrace_may_access() checks permissions\nbased on current credentials, it succeeds. However, if T begins exec\nimmediately afterwards, it becomes privileged and may change its memory\nmappings. Because get_robust_list() proceeds to access T->robust_list\nwithout synchronizing with exec() it may read user-space pointers from a\nnow-privileged process.\n\nThis violates the intended post-exec access restrictions and could\nexpose sensitive memory addresses or be used as a primitive in a larger\nexploit chain. Consequently, the race can lead to unauthorized\ndisclosure of information across privilege boundaries and poses a\npotential security risk.\n\nTake a read lock on signal->exec_update_lock prior to invoking\nptrace_may_access() and accessing the robust_list/compat_robust_list.\nThis ensures that the target task's exec state remains stable during the\ncheck, allowing for consistent and synchronized validation of\ncredentials.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/3b4222494489f6d4b8705a496dab03384b7ca998","https://git.kernel.org/stable/c/4aced32596ead1820b7dbd8e40d30b30dc1f3ad4","https://git.kernel.org/stable/c/6511984d1aa1360181bcafb1ca75df7f291ef237","https://git.kernel.org/stable/c/6b54082c3ed4dc9821cdf0edb17302355cc5bb45","https://git.kernel.org/stable/c/b524455a51feb6013df3a5dba3160487b2e8e22a"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:16:40.427100871+00:00"},"epss":{"cve":"CVE-2025-40341","score":0.00229,"percentile":0.13619,"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."]}