{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-22121", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-12-29T08:45:45.823Z", "datePublished": "2025-04-16T14:13:05.894Z", "dateUpdated": "2026-08-05T11:56:56.499Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:56:56.499Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: fix out-of-bound read in ext4_xattr_inode_dec_ref_all()\n\nThere's issue as follows:\nBUG: KASAN: use-after-free in ext4_xattr_inode_dec_ref_all+0x6ff/0x790\nRead of size 4 at addr ffff88807b003000 by task syz-executor.0/15172\n\nCPU: 3 PID: 15172 Comm: syz-executor.0\nCall Trace:\n __dump_stack lib/dump_stack.c:82 [inline]\n dump_stack+0xbe/0xfd lib/dump_stack.c:123\n print_address_description.constprop.0+0x1e/0x280 mm/kasan/report.c:400\n __kasan_report.cold+0x6c/0x84 mm/kasan/report.c:560\n kasan_report+0x3a/0x50 mm/kasan/report.c:585\n ext4_xattr_inode_dec_ref_all+0x6ff/0x790 fs/ext4/xattr.c:1137\n ext4_xattr_delete_inode+0x4c7/0xda0 fs/ext4/xattr.c:2896\n ext4_evict_inode+0xb3b/0x1670 fs/ext4/inode.c:323\n evict+0x39f/0x880 fs/inode.c:622\n iput_final fs/inode.c:1746 [inline]\n iput fs/inode.c:1772 [inline]\n iput+0x525/0x6c0 fs/inode.c:1758\n ext4_orphan_cleanup fs/ext4/super.c:3298 [inline]\n ext4_fill_super+0x8c57/0xba40 fs/ext4/super.c:5300\n mount_bdev+0x355/0x410 fs/super.c:1446\n legacy_get_tree+0xfe/0x220 fs/fs_context.c:611\n vfs_get_tree+0x8d/0x2f0 fs/super.c:1576\n do_new_mount fs/namespace.c:2983 [inline]\n path_mount+0x119a/0x1ad0 fs/namespace.c:3316\n do_mount+0xfc/0x110 fs/namespace.c:3329\n __do_sys_mount fs/namespace.c:3540 [inline]\n __se_sys_mount+0x219/0x2e0 fs/namespace.c:3514\n do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46\n entry_SYSCALL_64_after_hwframe+0x67/0xd1\n\nMemory state around the buggy address:\n ffff88807b002f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n ffff88807b002f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n>ffff88807b003000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff\n ^\n ffff88807b003080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff\n ffff88807b003100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff\n\nAbove issue happens as ext4_xattr_delete_inode() isn't check xattr\nis valid if xattr is in inode.\nTo solve above issue call xattr_check_inode() check if xattr if valid\nin inode. In fact, we can directly verify in ext4_iget_extra_inode(),\nso that there is no divergent verification." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.4, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - Exploitation requires the attacker-crafted ext4 image to be presented to the local kernel as a block device — a USB stick on an automounting desktop/kiosk, a loop/NBD/iSCSI-backed device, or a container/VM disk image — reaching the bug through the mount(2) syscall path. No network protocol handler is involved, and physical access is not strictly required since loop and network-block-backed images work equally well.\nAC:L - The attacker fully controls every byte of the on-disk image, including the ea_inode feature bit, the inode's i_extra_isize, the xattr magic, the entry array, and which inode sits last in its inode-table block so the walk runs off the end of the buffer_head page allocation. The corruption is deterministic at mount during orphan cleanup with no race to win and no dependency on kernel memory layout the attacker cannot influence.\nPR:N - The attacker needs no account or privilege on the target system — they only supply the malicious filesystem image, which is then mounted by root, by an automount daemon such as udisks2, or by a container/VM image-handling service acting on the attacker's data. All privileged operations along the path are performed by the victim system on the attacker's behalf.\nUI:N - On the common desktop, kiosk, and appliance configurations where udisks2/systemd automounts removable media, plugging in the device triggers the mount with no human participation, and the bug fires immediately during ext4_orphan_cleanup() inside ext4_fill_super() rather than requiring any subsequent file access. Container and VM image-mount services likewise mount attacker-supplied images unattended.\nS:U - The out-of-bounds read and write occur in kernel heap memory within the same kernel security authority that hosts the vulnerable ext4 code. There is no crossing of a VM, IOMMU, or sandbox boundary.\nC:H - The loop performs an unbounded (pre-mitigation) or several-byte-past-the-allocation (post-mitigation) out-of-bounds read of adjacent kernel heap memory past the inode-table buffer_head, and those leaked bytes are consumed as e_value_inum/e_hash/e_value_size values that steer subsequent inode lookups and quota accounting, making adjacent kernel memory contents observable through filesystem state and error output.\nI:H - `entry->e_value_inum = 0; entry->e_value_size = 0;` writes 8 zero bytes through an out-of-bounds entry pointer into adjacent kernel heap memory, and the OOB-derived inode numbers drive ext4_xattr_inode_dec_ref()/ext4_orphan_add() to decrement refcounts and orphan arbitrary inodes. This combination of controlled kernel heap zeroing plus arbitrary on-disk metadata corruption is a usable memory-corruption primitive, not a bounded misread.\nA:H - KASAN reproduces the issue as a use-after-free/out-of-bounds access past a page-sized buffer_head allocation during mount; on a production kernel the same access corrupts adjacent slab memory and the bogus inode ref-count decrements trigger EXT4-fs errors and oops/panic. The crash occurs during ext4_fill_super() and can be repeated on every mount attempt." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ext4/inode.c", "fs/ext4/xattr.c", "fs/ext4/xattr.h" ], "versions": [ { "version": "e50e5129f384ae282adebfb561189cdb19b81cee", "lessThan": "27202452b0bc942fdc3db72a44c4dcdab96d5b56", "status": "affected", "versionType": "git" }, { "version": "e50e5129f384ae282adebfb561189cdb19b81cee", "lessThan": "b374e9ecc92aaa7fb2ab221ee3ff5451118ab566", "status": "affected", "versionType": "git" }, { "version": "e50e5129f384ae282adebfb561189cdb19b81cee", "lessThan": "c000a8a9b5343a5ef867df173c6349672dacbd0f", "status": "affected", "versionType": "git" }, { "version": "e50e5129f384ae282adebfb561189cdb19b81cee", "lessThan": "3c591353956ffcace2cc74d09930774afed60619", "status": "affected", "versionType": "git" }, { "version": "e50e5129f384ae282adebfb561189cdb19b81cee", "lessThan": "098927a13fd918bd7c64c2de905350a1ad7b4a3a", "status": "affected", "versionType": "git" }, { "version": "e50e5129f384ae282adebfb561189cdb19b81cee", "lessThan": "0c8fbb6ffb3c8f5164572ca88e4ccb6cd6a41ca8", "status": "affected", "versionType": "git" }, { "version": "e50e5129f384ae282adebfb561189cdb19b81cee", "lessThan": "5701875f9609b000d91351eaa6bfd97fe2f157f4", "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/inode.c", "fs/ext4/xattr.c", "fs/ext4/xattr.h" ], "versions": [ { "version": "4.13", "status": "affected" }, { "version": "0", "lessThan": "4.13", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.248", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.198", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.161", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.120", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.59", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.14.2", "lessThanOrEqual": "6.14.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.15", "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": "4.13", "versionEndExcluding": "5.10.248" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.13", "versionEndExcluding": "5.15.198" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.13", "versionEndExcluding": "6.1.161" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.13", "versionEndExcluding": "6.6.120" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.13", "versionEndExcluding": "6.12.59" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.13", "versionEndExcluding": "6.14.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.13", "versionEndExcluding": "6.15" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/27202452b0bc942fdc3db72a44c4dcdab96d5b56" }, { "url": "https://git.kernel.org/stable/c/b374e9ecc92aaa7fb2ab221ee3ff5451118ab566" }, { "url": "https://git.kernel.org/stable/c/c000a8a9b5343a5ef867df173c6349672dacbd0f" }, { "url": "https://git.kernel.org/stable/c/3c591353956ffcace2cc74d09930774afed60619" }, { "url": "https://git.kernel.org/stable/c/098927a13fd918bd7c64c2de905350a1ad7b4a3a" }, { "url": "https://git.kernel.org/stable/c/0c8fbb6ffb3c8f5164572ca88e4ccb6cd6a41ca8" }, { "url": "https://git.kernel.org/stable/c/5701875f9609b000d91351eaa6bfd97fe2f157f4" } ], "title": "ext4: fix out-of-bound read in ext4_xattr_inode_dec_ref_all()", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "x_adpType": "supplier", "providerMetadata": { "orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-07-14T12:40:51.409Z" }, "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": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" } ], "references": [ { "url": "https://cert-portal.siemens.com/productcert/html/ssa-019113.html" } ] } ] } }