{"cve":"CVE-2025-68264","nvd":{"published":"2025-12-16T15:15:55.920","modified":"2026-10-15T02:18:11.060","status":"Deferred","description":"In the Linux kernel, the following vulnerability has been resolved:\n\next4: refresh inline data size before write operations\n\nThe cached ei->i_inline_size can become stale between the initial size\ncheck and when ext4_update_inline_data()/ext4_create_inline_data() use\nit. Although ext4_get_max_inline_size() reads the correct value at the\ntime of the check, concurrent xattr operations can modify i_inline_size\nbefore ext4_write_lock_xattr() is acquired.\n\nThis causes ext4_update_inline_data() and ext4_create_inline_data() to\nwork with stale capacity values, leading to a BUG_ON() crash in\next4_write_inline_data():\n\n  kernel BUG at fs/ext4/inline.c:1331!\n  BUG_ON(pos + len > EXT4_I(inode)->i_inline_size);\n\nThe race window:\n1. ext4_get_max_inline_size() reads i_inline_size = 60 (correct)\n2. Size check passes for 50-byte write\n3. [Another thread adds xattr, i_inline_size changes to 40]\n4. ext4_write_lock_xattr() acquires lock\n5. ext4_update_inline_data() uses stale i_inline_size = 60\n6. Attempts to write 50 bytes but only 40 bytes actually available\n7. BUG_ON() triggers\n\nFix this by recalculating i_inline_size via ext4_find_inline_data_nolock()\nimmediately after acquiring xattr_sem. This ensures ext4_update_inline_data()\nand ext4_create_inline_data() work with current values that are protected\nfrom concurrent modifications.\n\nThis is similar to commit a54c4613dac1 (\"ext4: fix race writing to an\ninline_data file while its xattrs are changing\") which fixed i_inline_off\nstaleness. This patch addresses the related i_inline_size staleness issue.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/1687a055a555347b002f406676a1aaae4668f242","https://git.kernel.org/stable/c/210ac60a86a3ad2c76ae60e0dc71c34af6e7ea0b","https://git.kernel.org/stable/c/43bf001f0fe4e59bba47c897505222f959f4a1cc","https://git.kernel.org/stable/c/54ab81ae5f218452e64470cd8a8139bb5880fe2b","https://git.kernel.org/stable/c/58df743faf21ceb1880f930aa5dd428e2a5e415d"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:17:07.138532058+00:00"},"epss":{"cve":"CVE-2025-68264","score":0.00224,"percentile":0.12857,"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."]}