{"id":"CVE-2025-40341","url":"https://www.cyber-defence.io/tools/cve/CVE-2025-40341","generatedAt":"2026-10-28T09:26:03.414Z","title":"In the Linux kernel, the following vulnerability has been resolved: futex: Don't leak robust_list pointer on exec race sys_get_robust_list() and compat_get_robust_list() use ptrace_may_access() to check if the calling task is allowed to access another…","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.","published":"2025-12-09T16:17:44.000Z","lastModified":"2026-10-14T21:10:00.000Z","status":"Deferred","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":null,"cwe":[],"affected":[],"epss":{"score":0.00229,"percentile":0.13675,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"unknown","text":"Not yet scored. NVD analysis is pending; check back once CVSS and EPSS values are published."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/3b4222494489f6d4b8705a496dab03384b7ca998","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4aced32596ead1820b7dbd8e40d30b30dc1f3ad4","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/6511984d1aa1360181bcafb1ca75df7f291ef237","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/6b54082c3ed4dc9821cdf0edb17302355cc5bb45","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/b524455a51feb6013df3a5dba3160487b2e8e22a","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2025-40341","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}