{"id":"CVE-2026-31598","title":"ocfs2: fix possible deadlock between unlink and dio_end_io_write","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: fix possible deadlock between unlink and dio_end_io_write\n\nocfs2_unlink takes orphan dir inode_lock first and then ip_alloc_sem,\nwhile in ocfs2_dio_end_io_write,…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= a86a72a4a4e0ec109a98e2737948864ed6794bf7 < 297d8d7bb6a2bf133d3a3636edbdf94101cbd719","Linux >= a86a72a4a4e0ec109a98e2737948864ed6794bf7 < 32630dee18c6bb2175c8a865a474749492eaf19c","Linux >= a86a72a4a4e0ec109a98e2737948864ed6794bf7 < 93f35419eb84d58820040642cb6e7528fe4aba7a","Linux >= a86a72a4a4e0ec109a98e2737948864ed6794bf7 < 4b80b5a838a32437f2cae0662578bac216a2c51a","Linux >= a86a72a4a4e0ec109a98e2737948864ed6794bf7 < 2b884d52273c60c298bd570163e8053657bbaff6","Linux >= a86a72a4a4e0ec109a98e2737948864ed6794bf7 < bc0fb5c7d54c78be43a536df0e20dee32adb27d3","Linux >= a86a72a4a4e0ec109a98e2737948864ed6794bf7 < f9fb1a7b635849322e1d7b7b6b26389778ec8e82","Linux >= a86a72a4a4e0ec109a98e2737948864ed6794bf7 < e049f7a9bd80b7319590789ea5e1c523d6339d91","Linux >= a86a72a4a4e0ec109a98e2737948864ed6794bf7 < b02da26a992db0c0e2559acbda0fc48d4a2fd337","Linux 4.6"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-10-16T15:11:06.751234Z"},"published":"2026-04-24","updated":"2026-10-16","sourceUpdated":"2026-10-16T15:20:16.438Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-31598","references":[{"url":"https://git.kernel.org/stable/c/297d8d7bb6a2bf133d3a3636edbdf94101cbd719"},{"url":"https://git.kernel.org/stable/c/32630dee18c6bb2175c8a865a474749492eaf19c"},{"url":"https://git.kernel.org/stable/c/93f35419eb84d58820040642cb6e7528fe4aba7a"},{"url":"https://git.kernel.org/stable/c/4b80b5a838a32437f2cae0662578bac216a2c51a"},{"url":"https://git.kernel.org/stable/c/2b884d52273c60c298bd570163e8053657bbaff6"},{"url":"https://git.kernel.org/stable/c/bc0fb5c7d54c78be43a536df0e20dee32adb27d3"},{"url":"https://git.kernel.org/stable/c/f9fb1a7b635849322e1d7b7b6b26389778ec8e82"},{"url":"https://git.kernel.org/stable/c/e049f7a9bd80b7319590789ea5e1c523d6339d91"},{"url":"https://git.kernel.org/stable/c/b02da26a992db0c0e2559acbda0fc48d4a2fd337"}],"tags":["cve.org"],"epss":0.00435,"epssPercentile":0.36356,"ingestedAt":"2026-10-16T17:24:46.663Z","slug":"CVE-2026-31598","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: fix possible deadlock between unlink and dio_end_io_write\n\nocfs2_unlink takes orphan dir inode_lock first and then ip_alloc_sem,\nwhile in ocfs2_dio_end_io_write, it acquires these locks in reverse order.\nThis creates an ABBA lock ordering violation on lock classes\nocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE] and\nocfs2_file_ip_alloc_sem_key.\n\nLock Chain #0 (orphan dir inode_lock -> ip_alloc_sem):\nocfs2_unlink\n  ocfs2_prepare_orphan_dir\n    ocfs2_lookup_lock_orphan_dir\n      inode_lock(orphan_dir_inode) <- lock A\n    __ocfs2_prepare_orphan_dir\n      ocfs2_prepare_dir_for_insert\n        ocfs2_extend_dir\n\t  ocfs2_expand_inline_dir\n\t    down_write(&oi->ip_alloc_sem) <- Lock B\n\nLock Chain #1 (ip_alloc_sem -> orphan dir inode_lock):\nocfs2_dio_end_io_write\n  down_write(&oi->ip_alloc_sem) <- Lock B\n  ocfs2_del_inode_from_orphan()\n    inode_lock(orphan_dir_inode) <- Lock A\n\nDeadlock Scenario:\n  CPU0 (unlink)                     CPU1 (dio_end_io_write)\n  ------                            ------\n  inode_lock(orphan_dir_inode)\n                                    down_write(ip_alloc_sem)\n  down_write(ip_alloc_sem)\n                                    inode_lock(orphan_dir_inode)\n\nSince ip_alloc_sem is to protect allocation changes, which is unrelated\nwith operations in ocfs2_del_inode_from_orphan.  So move\nocfs2_del_inode_from_orphan out of ip_alloc_sem to fix the deadlock.\n\n## Affected\n\n- `Linux >= a86a72a4a4e0ec109a98e2737948864ed6794bf7 < 297d8d7bb6a2bf133d3a3636edbdf94101cbd719`\n- `Linux >= a86a72a4a4e0ec109a98e2737948864ed6794bf7 < 32630dee18c6bb2175c8a865a474749492eaf19c`\n- `Linux >= a86a72a4a4e0ec109a98e2737948864ed6794bf7 < 93f35419eb84d58820040642cb6e7528fe4aba7a`\n- `Linux >= a86a72a4a4e0ec109a98e2737948864ed6794bf7 < 4b80b5a838a32437f2cae0662578bac216a2c51a`\n- `Linux >= a86a72a4a4e0ec109a98e2737948864ed6794bf7 < 2b884d52273c60c298bd570163e8053657bbaff6`\n- `Linux >= a86a72a4a4e0ec109a98e2737948864ed6794bf7 < bc0fb5c7d54c78be43a536df0e20dee32adb27d3`\n- `Linux >= a86a72a4a4e0ec109a98e2737948864ed6794bf7 < f9fb1a7b635849322e1d7b7b6b26389778ec8e82`\n- `Linux >= a86a72a4a4e0ec109a98e2737948864ed6794bf7 < e049f7a9bd80b7319590789ea5e1c523d6339d91`\n- `Linux >= a86a72a4a4e0ec109a98e2737948864ed6794bf7 < b02da26a992db0c0e2559acbda0fc48d4a2fd337`\n- `Linux 4.6`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}