{"id":"CVE-2025-40190","summary":"ext4: guard against EA inode refcount underflow in xattr update","details":"In the Linux kernel, the following vulnerability has been resolved:\n\next4: guard against EA inode refcount underflow in xattr update\n\nsyzkaller found a path where ext4_xattr_inode_update_ref() reads an EA\ninode refcount that is already \u003c= 0 and then applies ref_change (often\n-1). That lets the refcount underflow and we proceed with a bogus value,\ntriggering errors like:\n\n  EXT4-fs error: EA inode \u003cn\u003e ref underflow: ref_count=-1 ref_change=-1\n  EXT4-fs warning: ea_inode dec ref err=-117\n\nMake the invariant explicit: if the current refcount is non-positive,\ntreat this as on-disk corruption, emit ext4_error_inode(), and fail the\noperation with -EFSCORRUPTED instead of updating the refcount. Delete the\nWARN_ONCE() as negative refcounts are now impossible; keep error reporting\nin ext4_error_inode().\n\nThis prevents the underflow and the follow-on orphan/cleanup churn.","modified":"2026-04-02T12:48:18.982261Z","published":"2025-11-12T21:56:30.914Z","related":["SUSE-SU-2026:0278-1","SUSE-SU-2026:0281-1","SUSE-SU-2026:0315-1","SUSE-SU-2026:20207-1","SUSE-SU-2026:20220-1","SUSE-SU-2026:20228-1","SUSE-SU-2026:20477-1","SUSE-SU-2026:20498-1","SUSE-SU-2026:20845-1","SUSE-SU-2026:20876-1","openSUSE-SU-2026:20145-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/40xxx/CVE-2025-40190.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/1cfb3e4ddbdc8e02e637b8852540bd4718bf4814"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3d6269028246f4484bfed403c947a114bb583631"},{"type":"WEB","url":"https://git.kernel.org/stable/c/440b003f449a4ff2a00b08c8eab9ba5cd28f3943"},{"type":"WEB","url":"https://git.kernel.org/stable/c/505e69f76ac497e788f4ea0267826ec7266b40c8"},{"type":"WEB","url":"https://git.kernel.org/stable/c/57295e835408d8d425bef58da5253465db3d6888"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6b879c4c6bbaab03c0ad2a983953bd1410bb165e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/79ea7f3e11effe1bd9e753172981d9029133a278"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ea39e712c2f5ae148ee5515798ae03523673e002"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/40xxx/CVE-2025-40190.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-40190"},{"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":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2"},{"fixed":"ea39e712c2f5ae148ee5515798ae03523673e002"},{"fixed":"1cfb3e4ddbdc8e02e637b8852540bd4718bf4814"},{"fixed":"505e69f76ac497e788f4ea0267826ec7266b40c8"},{"fixed":"3d6269028246f4484bfed403c947a114bb583631"},{"fixed":"79ea7f3e11effe1bd9e753172981d9029133a278"},{"fixed":"6b879c4c6bbaab03c0ad2a983953bd1410bb165e"},{"fixed":"440b003f449a4ff2a00b08c8eab9ba5cd28f3943"},{"fixed":"57295e835408d8d425bef58da5253465db3d6888"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-40190.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.301"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.5.0"},{"fixed":"5.10.246"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.195"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.157"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.113"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.54"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.17.4"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-40190.json"}}],"schema_version":"1.7.5"}