{"id":"CVE-2026-64588","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-64588","summary":"fuse-uring: fix data races on ring->ready","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nfuse-uring: fix data races on ring->ready\n\nOn weakly-ordered architectures, the store to fiq->ops can be\nreordered past the store to ring->ready, allowing a CPU that sees\nring->ready == true via fuse_uring_ready() to dispatch requests\nthrough a stale fiq->ops pointer. Upgrade the store to\nsmp_store_release() and the load in fuse_uring_ready() to\nsmp_load_acquire() so that the preceding WRITE_ONCE(fiq->ops, ...)\nis visible to any CPU that observes ring->ready == true.\n\nAdditionally, fuse_uring_do_register() publishes ring->ready with\nWRITE_ONCE() but the fast-path check reads it with a plain load.\nThis is a marked-vs-unmarked access that KCSAN will flag. Wrap it in\nREAD_ONCE() to mark it without adding unnecessary ordering.\n\nAlso wrap the fc->ring load in fuse_uring_ready() in READ_ONCE() to\nprevent the compiler from reloading it between the NULL check and the\ndereference.","published":"2026-08-06T07:13:46.688Z","modified":"2026-08-08T03:32:29.049076497Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Linux","name":"Kernel","fixedVersion":"6.18.39"}],"fix":null,"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/46725a0056c884cf58a6897f222892807327d82d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b156bb9966972122b148acab8bdf415cdb8176a3"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d01a09b442cb786cd44ccc7c84d57e2856d6737c"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64588.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64588"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-08T03:32:29.049076497Z"}}