{"id":"CVE-2026-31598","state":"PUBLISHED","title":"ocfs2: fix possible deadlock between unlink and dio_end_io_write","description":"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, 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.","publishedAt":"2026-04-24T14:42:23.304Z","updatedAt":"2026-10-19T18:55:59.744Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"a86a72a4a4e0ec109a98e2737948864ed6794bf7","status":"affected","lessThan":"297d8d7bb6a2bf133d3a3636edbdf94101cbd719","versionType":"git"},{"version":"a86a72a4a4e0ec109a98e2737948864ed6794bf7","status":"affected","lessThan":"32630dee18c6bb2175c8a865a474749492eaf19c","versionType":"git"},{"version":"a86a72a4a4e0ec109a98e2737948864ed6794bf7","status":"affected","lessThan":"93f35419eb84d58820040642cb6e7528fe4aba7a","versionType":"git"},{"version":"a86a72a4a4e0ec109a98e2737948864ed6794bf7","status":"affected","lessThan":"4b80b5a838a32437f2cae0662578bac216a2c51a","versionType":"git"},{"version":"a86a72a4a4e0ec109a98e2737948864ed6794bf7","status":"affected","lessThan":"2b884d52273c60c298bd570163e8053657bbaff6","versionType":"git"},{"version":"a86a72a4a4e0ec109a98e2737948864ed6794bf7","status":"affected","lessThan":"bc0fb5c7d54c78be43a536df0e20dee32adb27d3","versionType":"git"},{"version":"a86a72a4a4e0ec109a98e2737948864ed6794bf7","status":"affected","lessThan":"f9fb1a7b635849322e1d7b7b6b26389778ec8e82","versionType":"git"},{"version":"a86a72a4a4e0ec109a98e2737948864ed6794bf7","status":"affected","lessThan":"e049f7a9bd80b7319590789ea5e1c523d6339d91","versionType":"git"},{"version":"a86a72a4a4e0ec109a98e2737948864ed6794bf7","status":"affected","lessThan":"b02da26a992db0c0e2559acbda0fc48d4a2fd337","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ocfs2/aops.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.6","versionType":"semver"},{"version":"5.10.258","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.209","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.175","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.136","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.83","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.24","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.14","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0.1","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ocfs2/aops.c"]}],"references":["https://git.kernel.org/stable/c/297d8d7bb6a2bf133d3a3636edbdf94101cbd719","https://git.kernel.org/stable/c/32630dee18c6bb2175c8a865a474749492eaf19c","https://git.kernel.org/stable/c/93f35419eb84d58820040642cb6e7528fe4aba7a","https://git.kernel.org/stable/c/4b80b5a838a32437f2cae0662578bac216a2c51a","https://git.kernel.org/stable/c/2b884d52273c60c298bd570163e8053657bbaff6","https://git.kernel.org/stable/c/bc0fb5c7d54c78be43a536df0e20dee32adb27d3","https://git.kernel.org/stable/c/f9fb1a7b635849322e1d7b7b6b26389778ec8e82","https://git.kernel.org/stable/c/e049f7a9bd80b7319590789ea5e1c523d6339d91","https://git.kernel.org/stable/c/b02da26a992db0c0e2559acbda0fc48d4a2fd337"],"weaknesses":["CWE-362"],"ingestedAt":"2026-10-29T20:11:40.391Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/31xxx/CVE-2026-31598.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-31598","state":"PUBLISHED","datePublished":"2026-04-24T14:42:23.304Z","dateUpdated":"2026-10-19T18:55:59.744Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-03-09T15:48:24.121Z"},"containers":{"cna":{"title":"ocfs2: fix possible deadlock between unlink and dio_end_io_write","descriptions":[{"lang":"en","value":"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, 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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"a86a72a4a4e0ec109a98e2737948864ed6794bf7","status":"affected","lessThan":"297d8d7bb6a2bf133d3a3636edbdf94101cbd719","versionType":"git"},{"version":"a86a72a4a4e0ec109a98e2737948864ed6794bf7","status":"affected","lessThan":"32630dee18c6bb2175c8a865a474749492eaf19c","versionType":"git"},{"version":"a86a72a4a4e0ec109a98e2737948864ed6794bf7","status":"affected","lessThan":"93f35419eb84d58820040642cb6e7528fe4aba7a","versionType":"git"},{"version":"a86a72a4a4e0ec109a98e2737948864ed6794bf7","status":"affected","lessThan":"4b80b5a838a32437f2cae0662578bac216a2c51a","versionType":"git"},{"version":"a86a72a4a4e0ec109a98e2737948864ed6794bf7","status":"affected","lessThan":"2b884d52273c60c298bd570163e8053657bbaff6","versionType":"git"},{"version":"a86a72a4a4e0ec109a98e2737948864ed6794bf7","status":"affected","lessThan":"bc0fb5c7d54c78be43a536df0e20dee32adb27d3","versionType":"git"},{"version":"a86a72a4a4e0ec109a98e2737948864ed6794bf7","status":"affected","lessThan":"f9fb1a7b635849322e1d7b7b6b26389778ec8e82","versionType":"git"},{"version":"a86a72a4a4e0ec109a98e2737948864ed6794bf7","status":"affected","lessThan":"e049f7a9bd80b7319590789ea5e1c523d6339d91","versionType":"git"},{"version":"a86a72a4a4e0ec109a98e2737948864ed6794bf7","status":"affected","lessThan":"b02da26a992db0c0e2559acbda0fc48d4a2fd337","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ocfs2/aops.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.6","versionType":"semver"},{"version":"5.10.258","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.209","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.175","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.136","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.83","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.24","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.14","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0.1","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ocfs2/aops.c"]}],"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"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - Although the core bug is in ocfs2 filesystem code, ocfs2 is exportable and nfsd can issue direct writes with IOCB_DIRECT while remote REMOVE operations reach vfs_unlink, making the vulnerable lock chains reachable over the network on a writable exported ocfs2 volume.\nAC:L - The bug is an ABBA deadlock where the attacker can drive both sides with concurrent extending direct writes and unlink/remove operations. Once the target deployment exposes those operations, winning the race is attacker-controlled.\nPR:N - A remote NFS client can trigger the operations through an exported writable share without kernel capabilities on the target. In permissive or anonymous export scenarios, no prior authenticated privileges are required.\nUI:N - No victim user action is required after the vulnerable service/filesystem is available. The attacker can send the write and remove operations directly.\nS:U - The impact remains within the same kernel/filesystem security authority. There is no VM escape, sandbox boundary crossing, or separate security scope.\nC:N - The issue is a lock-ordering deadlock, not memory corruption or information disclosure. It does not provide a read primitive or leak data.\nI:N - The vulnerable behavior does not corrupt memory or allow unauthorized data modification. It only causes threads to block on locks.\nA:H - The deadlock can permanently hang ocfs2 operations and affected kernel worker/syscall contexts. A kernel/filesystem hang is a high availability impact."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:23:42.417Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"5.10.258"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"5.15.209"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"6.1.175"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"6.6.136"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"6.12.83"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"6.18.24"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"6.19.14"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"7.0.1"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-31598","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-10-16T15:11:06.751234Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-362","lang":"en","type":"CWE","description":"CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T18:55:59.744Z"}}]}}}