{"id":"CVE-2026-31450","revision":"7e909532e63c447b9f71ca44ec03a1b5","records":[{"revision":"7e909532e63c447b9f71ca44ec03a1b5","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-31450","aliases":[],"title":"ext4: publish jinode after initialization","description":"In the Linux kernel, the following vulnerability has been resolved:\n\next4: publish jinode after initialization\n\next4_inode_attach_jinode() publishes ei->jinode to concurrent users.\nIt used to set ei->jinode before jbd2_journal_init_jbd_inode(),\nallowing a reader to observe a non-NULL jinode with i_vfs_inode\nstill unset.\n\nThe fast commit flush path can then pass this jinode to\njbd2_wait_inode_data(), which dereferences i_vfs_inode->i_mapping and\nmay crash.\n\nBelow is the crash I observe:\n```\nBUG: unable to handle page fault for address: 000000010beb47f4\nPGD 110e51067 P4D 110e51067 PUD 0\nOops: Oops: 0000 [#1] SMP NOPTI\nCPU: 1 UID: 0 PID: 4850 Comm: fc_fsync_bench_ Not tainted 6.18.0-00764-g795a690c06a5 #1 PREEMPT(voluntary)\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.17.0-2-2 04/01/2014\nRIP: 0010:xas_find_marked+0x3d/0x2e0\nCode: e0 03 48 83 f8 02 0f 84 f0 01 00 00 48 8b 47 08 48 89 c3 48 39 c6 0f 82 fd 01 00 00 48 85 c9 74 3d 48 83 f9 03 77 63 4c 8b 0f <49> 8b 71 08 48 c7 47 18 00 00 00 00 48 89 f1 83 e1 03 48 83 f9 02\nRSP: 0018:ffffbbee806e7bf0 EFLAGS: 00010246\nRAX: 000000000010beb4 RBX: 000000000010beb4 RCX: 0000000000000003\nRDX: 0000000000000001 RSI: 0000002000300000 RDI: ffffbbee806e7c10\nRBP: 0000000000000001 R08: 0000002000300000 R09: 000000010beb47ec\nR10: ffff9ea494590090 R11: 0000000000000000 R12: 0000002000300000\nR13: ffffbbee806e7c90 R14: ffff9ea494513788 R15: ffffbbee806e7c88\nFS: 00007fc2f9e3e6c0(0000) GS:ffff9ea6b1444000(0000) knlGS:0000000000000000\nCS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 000000010beb47f4 CR3: 0000000119ac5000 CR4: 0000000000750ef0\nPKRU: 55555554\nCall Trace:\n<TASK>\nfilemap_get_folios_tag+0x87/0x2a0\n__filemap_fdatawait_range+0x5f/0xd0\n? srso_alias_return_thunk+0x5/0xfbef5\n? __schedule+0x3e7/0x10c0\n? srso_alias_return_thunk+0x5/0xfbef5\n? srso_alias_return_thunk+0x5/0xfbef5\n? srso_alias_return_thunk+0x5/0xfbef5\n? preempt_count_sub+0x5f/0x80\n? srso_alias_return_thunk+0x5/0xfbef5\n? cap_safe_nice+0x37/0x70\n? srso_alias_return_thunk+0x5/0xfbef5\n? preempt_count_sub+0x5f/0x80\n? srso_alias_return_thunk+0x5/0xfbef5\nfilemap_fdatawait_range_keep_errors+0x12/0x40\next4_fc_commit+0x697/0x8b0\n? ext4_file_write_iter+0x64b/0x950\n? srso_alias_return_thunk+0x5/0xfbef5\n? preempt_count_sub+0x5f/0x80\n? srso_alias_return_thunk+0x5/0xfbef5\n? vfs_write+0x356/0x480\n? srso_alias_return_thunk+0x5/0xfbef5\n? preempt_count_sub+0x5f/0x80\next4_sync_file+0xf7/0x370\ndo_fsync+0x3b/0x80\n? syscall_trace_enter+0x108/0x1d0\n__x64_sys_fdatasync+0x16/0x20\ndo_syscall_64+0x62/0x2c0\nentry_SYSCALL_64_after_hwframe+0x76/0x7e\n...\n```\n\nFix this by initializing the jbd2_inode first.\nUse smp_wmb() and WRITE_ONCE() to publish ei->jinode after\ninitialization. Readers use READ_ONCE() to fetch the pointer.","state":0,"publishedAt":"2026-04-22T13:53:45.532+00:00","modifiedAt":"2026-10-19T18:35:49.024+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"fs/ext4/fast_commit.c\",\n                        \"fs/ext4/inode.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"a361293f5fedea0016a10599f409631a15d47ee7\",\n                            \"lessThan\": \"2d2b648960147d078b000b9a7494017082024366\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"a361293f5fedea0016a10599f409631a15d47ee7\",\n                            \"lessThan\": \"e4325e84727e539c8597bd5b8491349f57f7fb17\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"a361293f5fedea0016a10599f409631a15d47ee7\",\n                            \"lessThan\": \"be54c0055407a73b60349c093c8ce621cb8fa232\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"a361293f5fedea0016a10599f409631a15d47ee7\",\n                            \"lessThan\": \"a070d5a872ffe0e0fe5c46eda6386140ded39adb\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"a361293f5fedea0016a10599f409631a15d47ee7\",\n                            \"lessThan\": \"e76bcb727e4874a2f9d0297f8e3f8eced89b0764\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"a361293f5fedea0016a10599f409631a15d47ee7\",\n                            \"lessThan\": \"4855a59e21789c79f003a9b5f4135c95a7495c6b\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"a361293f5fedea0016a10599f409631a15d47ee7\",\n                            \"lessThan\": \"33f486987af21531a7b18973d11795ede3da9ddd\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"a361293f5fedea0016a10599f409631a15d47ee7\",\n                            \"lessThan\": \"1aec30021edd410b986c156f195f3d23959a9d11\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"fs/ext4/fast_commit.c\",\n                        \"fs/ext4/inode.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"3.11\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"3.11\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.253\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.203\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.168\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.134\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.81\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.21\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.19.11\",\n                            \"lessThanOrEqual\": \"6.19.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.0\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":8.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/2d2b648960147d078b000b9a7494017082024366","https://git.kernel.org/stable/c/e4325e84727e539c8597bd5b8491349f57f7fb17","https://git.kernel.org/stable/c/be54c0055407a73b60349c093c8ce621cb8fa232","https://git.kernel.org/stable/c/a070d5a872ffe0e0fe5c46eda6386140ded39adb","https://git.kernel.org/stable/c/e76bcb727e4874a2f9d0297f8e3f8eced89b0764","https://git.kernel.org/stable/c/4855a59e21789c79f003a9b5f4135c95a7495c6b","https://git.kernel.org/stable/c/33f486987af21531a7b18973d11795ede3da9ddd","https://git.kernel.org/stable/c/1aec30021edd410b986c156f195f3d23959a9d11"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-31450","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-31450","identifiers":["CVE-2026-31450"]},"retained":false,"historicalAffected":[]}],"coverage":[]}