{"id":"CVE-2026-23415","summary":"futex: Fix UaF between futex_key_to_node_opt() and vma_replace_policy()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nfutex: Fix UaF between futex_key_to_node_opt() and vma_replace_policy()\n\nDuring futex_key_to_node_opt() execution, vma-\u003evm_policy is read under\nspeculative mmap lock and RCU. Concurrently, mbind() may call\nvma_replace_policy() which frees the old mempolicy immediately via\nkmem_cache_free().\n\nThis creates a race where __futex_key_to_node() dereferences a freed\nmempolicy pointer, causing a use-after-free read of mpol-\u003emode.\n\n[  151.412631] BUG: KASAN: slab-use-after-free in __futex_key_to_node (kernel/futex/core.c:349)\n[  151.414046] Read of size 2 at addr ffff888001c49634 by task e/87\n\n[  151.415969] Call Trace:\n\n[  151.416732]  __asan_load2 (mm/kasan/generic.c:271)\n[  151.416777]  __futex_key_to_node (kernel/futex/core.c:349)\n[  151.416822]  get_futex_key (kernel/futex/core.c:374 kernel/futex/core.c:386 kernel/futex/core.c:593)\n\nFix by adding rcu to __mpol_put().","modified":"2026-07-15T01:48:58.305472748Z","published":"2026-04-02T11:40:56.476Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23415.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/190a8c48ff623c3d67cb295b4536a660db2012aa"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7e196194ea27bd49adf3551e2aceb83498eb73fe"},{"type":"WEB","url":"https://git.kernel.org/stable/c/853f70c67d1b37e368fdcb3e328c4b8c04f53ac0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23415.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-23415"},{"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":"c042c505210dc3453f378df432c10fff3d471bc5"},{"fixed":"853f70c67d1b37e368fdcb3e328c4b8c04f53ac0"},{"fixed":"7e196194ea27bd49adf3551e2aceb83498eb73fe"},{"fixed":"190a8c48ff623c3d67cb295b4536a660db2012aa"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-23415.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.16.0"},{"fixed":"6.18.21"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"6.19.11"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-23415.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}