{"cve":"CVE-2023-53511","nvd":{"published":"2025-10-01T12:15:55.030","modified":"2026-06-17T06:45:30.170","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring: fix fget leak when fs don't support nowait buffered read\n\nHeming reported a BUG when using io_uring doing link-cp on ocfs2. [1]\n\nDo the following steps can reproduce this BUG:\nmount -t ocfs2 /dev/vdc /mnt/ocfs2\ncp testfile /mnt/ocfs2/\n./link-cp /mnt/ocfs2/testfile /mnt/ocfs2/testfile.1\numount /mnt/ocfs2\n\nThen umount will fail, and it outputs:\numount: /mnt/ocfs2: target is busy.\n\nWhile tracing umount, it blames mnt_get_count() not return as expected.\nDo a deep investigation for fget()/fput() on related code flow, I've\nfinally found that fget() leaks since ocfs2 doesn't support nowait\nbuffered read.\n\nio_issue_sqe\n|-io_assign_file  // do fget() first\n  |-io_read\n  |-io_iter_do_read\n    |-ocfs2_file_read_iter  // return -EOPNOTSUPP\n  |-kiocb_done\n    |-io_rw_done\n      |-__io_complete_rw_common  // set REQ_F_REISSUE\n    |-io_resubmit_prep\n      |-io_req_prep_async  // override req->file, leak happens\n\nThis was introduced by commit a196c78b5443 in v5.18. Fix it by don't\nre-assign req->file if it has already been assigned.\n\n[1] https://lore.kernel.org/ocfs2-devel/ab580a75-91c8-d68a-3455-40361be1bfa8@linux.alibaba.com/T/#t","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-401"],"references":["https://git.kernel.org/stable/c/10fb2e16ee6ffaf1716b9e90d007e6b300bfa457","https://git.kernel.org/stable/c/54aa7f2330b82884f4a1afce0220add6e8312f8b","https://git.kernel.org/stable/c/75a499fc9d66a32271e2b3e4ca71156e8ad3b484"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:11:26.888974865+00:00"},"epss":{"cve":"CVE-2023-53511","score":0.00146,"percentile":0.03862,"date":"2026-10-31"},"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."]}