{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-71161", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-01-13T15:30:19.665Z", "datePublished": "2026-01-23T15:23:59.464Z", "dateUpdated": "2026-08-05T12:12:26.264Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:12:26.264Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndm-verity: disable recursive forward error correction\n\nThere are two problems with the recursive correction:\n\n1. It may cause denial-of-service. In fec_read_bufs, there is a loop that\nhas 253 iterations. For each iteration, we may call verity_hash_for_block\nrecursively. There is a limit of 4 nested recursions - that means that\nthere may be at most 253^4 (4 billion) iterations. Red Hat QE team\nactually created an image that pushes dm-verity to this limit - and this\nimage just makes the udev-worker process get stuck in the 'D' state.\n\n2. It doesn't work. In fec_read_bufs we store data into the variable\n\"fio->bufs\", but fio bufs is shared between recursive invocations, if\n\"verity_hash_for_block\" invoked correction recursively, it would\noverwrite partially filled fio->bufs." } ], "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 - In a reasonable cloud or network-boot deployment, dm-verity data, hash, and FEC devices can be NBD-backed, allowing attacker-controlled TCP replies to supply the crafted blocks directly to the verification path.\nAC:L - A static crafted image deterministically drives FEC scanning into as many as 253^4 recursive iterations, as demonstrated by Red Hat QE. No race or uncontrollable memory layout is required.\nPR:N - DM table creation requires CAP_SYS_ADMIN in the initial user namespace, but that is victim-side setup. A malicious configured network-block peer requires no account or privilege on the affected system to return crafted blocks.\nUI:N - Once the mapping is active, automatic udev probing, boot-time access, or ordinary filesystem I/O triggers FEC without requiring a user action.\nS:U - The vulnerable processing and resulting availability loss occur within the same kernel security authority, without crossing a VM, IOMMU, or sandbox boundary.\nC:N - Recursive calls only clobber bounded per-I/O Reed-Solomon working data, and corrected output is cryptographically revalidated before being copied to its destination. The flaw provides no disclosure or read primitive.\nI:N - Although nested decoding corrupts outer intermediate results, the wanted digest is checked before corrected data is used, so failure produces an I/O error rather than attacker-selected data. No arbitrary-write or control-flow primitive results from this flaw.\nA:H - The crafted blocks can force approximately 4.1 billion iterations and leave I/O submitters such as udev workers blocked in uninterruptible sleep. On a boot or operational image this can prevent startup or render the device and dependent services unavailable." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/md/dm-verity-fec.c", "drivers/md/dm-verity-fec.h", "drivers/md/dm-verity-target.c" ], "versions": [ { "version": "a739ff3f543afbb4a041c16cd0182c8e8d366e70", "lessThan": "8b821ca892cfeeaf0bedc9fc72717294f67144d5", "status": "affected", "versionType": "git" }, { "version": "a739ff3f543afbb4a041c16cd0182c8e8d366e70", "lessThan": "e227d2b229c7529bd98d348efc55262ccf24ab35", "status": "affected", "versionType": "git" }, { "version": "a739ff3f543afbb4a041c16cd0182c8e8d366e70", "lessThan": "897d9006e75f46f8bd7df78faa424327ae6a4bcf", "status": "affected", "versionType": "git" }, { "version": "a739ff3f543afbb4a041c16cd0182c8e8d366e70", "lessThan": "4220cb37406915c926c0e4a3dbab77cd9cceeb1e", "status": "affected", "versionType": "git" }, { "version": "a739ff3f543afbb4a041c16cd0182c8e8d366e70", "lessThan": "232948cf600fba69aff36b25d85ef91a73a35756", "status": "affected", "versionType": "git" }, { "version": "a739ff3f543afbb4a041c16cd0182c8e8d366e70", "lessThan": "d9f3e47d3fae0c101d9094bc956ed24e7a0ee801", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/md/dm-verity-fec.c", "drivers/md/dm-verity-fec.h", "drivers/md/dm-verity-target.c" ], "versions": [ { "version": "4.5", "status": "affected" }, { "version": "0", "lessThan": "4.5", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.209", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.167", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.130", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.78", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.6", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19", "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": "4.5", "versionEndExcluding": "5.15.209" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.5", "versionEndExcluding": "6.1.167" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.5", "versionEndExcluding": "6.6.130" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.5", "versionEndExcluding": "6.12.78" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.5", "versionEndExcluding": "6.18.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.5", "versionEndExcluding": "6.19" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/8b821ca892cfeeaf0bedc9fc72717294f67144d5" }, { "url": "https://git.kernel.org/stable/c/e227d2b229c7529bd98d348efc55262ccf24ab35" }, { "url": "https://git.kernel.org/stable/c/897d9006e75f46f8bd7df78faa424327ae6a4bcf" }, { "url": "https://git.kernel.org/stable/c/4220cb37406915c926c0e4a3dbab77cd9cceeb1e" }, { "url": "https://git.kernel.org/stable/c/232948cf600fba69aff36b25d85ef91a73a35756" }, { "url": "https://git.kernel.org/stable/c/d9f3e47d3fae0c101d9094bc956ed24e7a0ee801" } ], "title": "dm-verity: disable recursive forward error correction", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "x_adpType": "supplier", "providerMetadata": { "orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-07-14T12:44:48.463Z" }, "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 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