{"cve":"CVE-2025-21887","nvd":{"published":"2025-03-27T15:15:56.603","modified":"2026-10-15T02:17:41.130","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\novl: fix UAF in ovl_dentry_update_reval by moving dput() in ovl_link_up\n\nThe issue was caused by dput(upper) being called before\novl_dentry_update_reval(), while upper->d_flags was still\naccessed in ovl_dentry_remote().\n\nMove dput(upper) after its last use to prevent use-after-free.\n\nBUG: KASAN: slab-use-after-free in ovl_dentry_remote fs/overlayfs/util.c:162 [inline]\nBUG: KASAN: slab-use-after-free in ovl_dentry_update_reval+0xd2/0xf0 fs/overlayfs/util.c:167\n\nCall Trace:\n <TASK>\n __dump_stack lib/dump_stack.c:88 [inline]\n dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114\n print_address_description mm/kasan/report.c:377 [inline]\n print_report+0xc3/0x620 mm/kasan/report.c:488\n kasan_report+0xd9/0x110 mm/kasan/report.c:601\n ovl_dentry_remote fs/overlayfs/util.c:162 [inline]\n ovl_dentry_update_reval+0xd2/0xf0 fs/overlayfs/util.c:167\n ovl_link_up fs/overlayfs/copy_up.c:610 [inline]\n ovl_copy_up_one+0x2105/0x3490 fs/overlayfs/copy_up.c:1170\n ovl_copy_up_flags+0x18d/0x200 fs/overlayfs/copy_up.c:1223\n ovl_rename+0x39e/0x18c0 fs/overlayfs/dir.c:1136\n vfs_rename+0xf84/0x20a0 fs/namei.c:4893\n...\n </TASK>","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":["CWE-416"],"references":["https://git.kernel.org/stable/c/3594aad97e7be2557ca9fa9c931b206b604028c8","https://git.kernel.org/stable/c/4b49d939b5a79117f939b77cc67efae2694d9799","https://git.kernel.org/stable/c/60b4b5c1277fc491da9e1e7abab307bfa39c2db7","https://git.kernel.org/stable/c/64455c8051c3aedc71abb7ec8d47c80301f99f00","https://git.kernel.org/stable/c/a7c41830ffcd17b2177a95a9b99b270302090c35"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:00:28.034033815+00:00"},"epss":{"cve":"CVE-2025-21887","score":0.00223,"percentile":0.12795,"date":"2026-10-25"},"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."]}