{"id":"AZL-72455","summary":"CVE-2025-68264 affecting package kernel for versions less than 6.6.121.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\next4: refresh inline data size before write operations\n\nThe cached ei-\u003ei_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 \u003e EXT4_I(inode)-\u003ei_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.","modified":"2026-04-01T05:22:10.207308Z","published":"2025-12-16T15:15:55Z","upstream":["CVE-2025-68264"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-68264"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.121.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-72455.json"}}],"schema_version":"1.7.5"}