{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-31450", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-03-09T15:48:24.091Z", "datePublished": "2026-04-22T13:53:45.532Z", "dateUpdated": "2026-08-05T12:22:40.995Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:22:40.995Z" }, "descriptions": [ { "lang": "en", "value": "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\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." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - In a reasonable server deployment, an ext4 filesystem with fast commits can be exported through in-kernel NFS or ksmbd, whose remote write/commit/flush paths call VFS fsync into ext4. Remote clients can therefore reach the vulnerable fast-commit flush path over the network.\nAC:L - The bug is a race, but the attacker can drive both sides with concurrent open/write/truncate and fsync/fdatasync or network flush/commit operations. Fast commit being enabled is a deployment condition for the affected ext4 configuration, not an uncontrollable exploitation condition.\nPR:L - The attacker needs permission to write and sync a file on the affected ext4 filesystem or exported share. No kernel capability or administrator privilege is required once such filesystem access is available.\nUI:N - Exploitation is triggered entirely by attacker-controlled file operations. No separate victim action is required.\nS:U - The impact remains within the vulnerable kernel and filesystem security authority. This is not a VM escape, IOMMU bypass, or cross-scope boundary violation.\nC:H - The race exposes an uninitialized slab-allocated jbd2_inode to consumers, allowing stale kernel pointers and ranges to be interpreted by writeback/wait paths. Under the required higher-severity rule, this UAF-like invalid object use is treated as capable of enabling kernel memory disclosure primitives.\nI:H - The same stale jbd2_inode fields can drive ext4/jbd2 writeback callbacks through an invalid or stale inode pointer. Under the required higher-severity rule, this kernel object misuse is treated as potentially exploitable for memory corruption or arbitrary modification.\nA:H - The demonstrated failure is a kernel oops/page fault in the fast commit fsync path. A local or remote authorized attacker can repeatedly trigger the crash, causing high availability impact." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ext4/fast_commit.c", "fs/ext4/inode.c" ], "versions": [ { "version": "a361293f5fedea0016a10599f409631a15d47ee7", "lessThan": "2d2b648960147d078b000b9a7494017082024366", "status": "affected", "versionType": "git" }, { "version": "a361293f5fedea0016a10599f409631a15d47ee7", "lessThan": "e4325e84727e539c8597bd5b8491349f57f7fb17", "status": "affected", "versionType": "git" }, { "version": "a361293f5fedea0016a10599f409631a15d47ee7", "lessThan": "be54c0055407a73b60349c093c8ce621cb8fa232", "status": "affected", "versionType": "git" }, { "version": "a361293f5fedea0016a10599f409631a15d47ee7", "lessThan": "a070d5a872ffe0e0fe5c46eda6386140ded39adb", "status": "affected", "versionType": "git" }, { "version": "a361293f5fedea0016a10599f409631a15d47ee7", "lessThan": "e76bcb727e4874a2f9d0297f8e3f8eced89b0764", "status": "affected", "versionType": "git" }, { "version": "a361293f5fedea0016a10599f409631a15d47ee7", "lessThan": "4855a59e21789c79f003a9b5f4135c95a7495c6b", "status": "affected", "versionType": "git" }, { "version": "a361293f5fedea0016a10599f409631a15d47ee7", "lessThan": "33f486987af21531a7b18973d11795ede3da9ddd", "status": "affected", "versionType": "git" }, { "version": "a361293f5fedea0016a10599f409631a15d47ee7", "lessThan": "1aec30021edd410b986c156f195f3d23959a9d11", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ext4/fast_commit.c", "fs/ext4/inode.c" ], "versions": [ { "version": "3.11", "status": "affected" }, { "version": "0", "lessThan": "3.11", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.253", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.203", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.168", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.134", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.81", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.21", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19.11", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.11", "versionEndExcluding": "5.10.253" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.11", "versionEndExcluding": "5.15.203" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.11", "versionEndExcluding": "6.1.168" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.11", "versionEndExcluding": "6.6.134" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.11", "versionEndExcluding": "6.12.81" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.11", "versionEndExcluding": "6.18.21" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.11", "versionEndExcluding": "6.19.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.11", "versionEndExcluding": "7.0" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/2d2b648960147d078b000b9a7494017082024366" }, { "url": "https://git.kernel.org/stable/c/e4325e84727e539c8597bd5b8491349f57f7fb17" }, { "url": "https://git.kernel.org/stable/c/be54c0055407a73b60349c093c8ce621cb8fa232" }, { "url": "https://git.kernel.org/stable/c/a070d5a872ffe0e0fe5c46eda6386140ded39adb" }, { "url": "https://git.kernel.org/stable/c/e76bcb727e4874a2f9d0297f8e3f8eced89b0764" }, { "url": "https://git.kernel.org/stable/c/4855a59e21789c79f003a9b5f4135c95a7495c6b" }, { "url": "https://git.kernel.org/stable/c/33f486987af21531a7b18973d11795ede3da9ddd" }, { "url": "https://git.kernel.org/stable/c/1aec30021edd410b986c156f195f3d23959a9d11" } ], "title": "ext4: publish jinode after initialization", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "x_adpType": "supplier", "providerMetadata": { "orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-07-14T12:47:55.794Z" }, "affected": [ { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.5", "lessThan": "*", 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