{"id":"CVE-2026-90162","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-90162","summary":"ksmbd: defer publishing granted locks to prevent UAF/double-free race","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: defer publishing granted locks to prevent UAF/double-free race\n\nIn smb2_lock(), mid-batch granted locks are published to connection-wide\n(conn->lock_list) and file-wide (fp->lock_list) lists immediately upon\nvfs_lock_file() success, while also remaining tracked on the stack-local\nrollback_list.\n\nIf a subsequent element in the same SMB2_LOCK request array fails\nvalidation or execution, the thread jumps to out: and walks\nrollback_list to undo previously granted locks. However, because the\ngranted lock was already published to conn->lock_list, a concurrent\nUNLOCK request on the same connection can find the lock object and\nkfree() it before the rollback loop executes.\n\nWhen the granting thread subsequently walks rollback_list, it\ndereferences and frees the already-freed ksmbd_lock structure, resulting\nin a Use-After-Free and Double-Free (on both ksmbd_lock and struct\nfile_lock).\n\nFix this by deferring the publication of granted locks to\nconn->lock_list and fp->lock_list until after the entire array of lock\nelements has been processed without error. Mid-batch grants remain\ntracked exclusively on the request-local rollback_list until the whole\nbatch succeeds, eliminating the race window.","published":"2026-09-17T16:06:53.136Z","modified":"2026-09-19T03:47:24.908836430Z","cvss":{"score":8.8,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Linux","name":"Kernel","fixedVersion":"7.2.6"}],"fix":null,"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/29f74f0f2e6df3b393b7b66e810136d0c64e3c59"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a1d26dfb32919088e3638dca01068df3c4507433"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90162.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-90162"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-19T03:47:24.908836430Z"}}