{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-37984", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T04:51:23.976Z", "datePublished": "2025-05-20T17:09:18.321Z", "dateUpdated": "2026-08-05T11:58:45.966Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:58:45.966Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: ecdsa - Harden against integer overflows in DIV_ROUND_UP()\n\nHerbert notes that DIV_ROUND_UP() may overflow unnecessarily if an ecdsa\nimplementation's ->key_size() callback returns an unusually large value.\nHerbert instead suggests (for a division by 8):\n\n X / 8 + !!(X & 7)\n\nBased on this formula, introduce a generic DIV_ROUND_UP_POW2() macro and\nuse it in lieu of DIV_ROUND_UP() for ->key_size() return values.\n\nAdditionally, use the macro in ecc_digits_from_bytes(), whose \"nbytes\"\nparameter is a ->key_size() return value in some instances, or a\nuser-specified ASN.1 length in the case of ecdsa_get_signature_rs()." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The affected code is the in-kernel ECDSA signature-verification path, entered from userspace via `add_key(\"asymmetric\", ...)`/`keyctl(KEYCTL_PKEY_VERIFY)` or local X.509/PKCS#7 verification. No in-kernel network consumer (ksmbd, nfsd, TLS, Bluetooth) performs ECDSA certificate verification, so the flaw is only reachable through local syscalls.\nAC:H - The `DIV_ROUND_UP()` wrap requires a value above `UINT_MAX - 7`, but every in-tree caller bounds its input — `ecdsa_get_signature_rs()` rejects `vlen > ndigits*8 + 1`, the ASN.1 decoder caps `vlen` at the buffer length, and `ecdsa_key_size()` is fixed at ≤66 bytes by the curve's `nbits`. Triggering it depends on an ECDSA implementation whose `->key_size()` callback reports an ~4 GB key, a precondition entirely outside the attacker's control and absent from any standard configuration.\nPR:L - The verification path is reachable by any unprivileged local user, who may add a crafted self-signed X.509 certificate to their own session keyring and then submit arbitrary signature blobs via `KEYCTL_PKEY_VERIFY`; no capability or namespace privilege is required.\nUI:N - The attacker drives the entire sequence through its own `add_key`/`keyctl` syscalls with attacker-supplied key and signature data; no victim action or cooperating process is needed.\nS:U - The resulting corruption is confined to kernel memory within the same kernel that runs the flawed code; no VM, hypervisor, IOMMU, or sandbox boundary is crossed.\nC:H - An underflowed `ndigits` sends `ecc_swap_digits()` iterating up to `0xFFFFFFFF` digits, reading and writing far outside the `ecdsa_raw_sig`/`pub_key` buffers, and the converted digits feed back into signature verification — an unbounded out-of-bounds access that could expose adjacent kernel memory.\nI:H - `out[--ndigits]` with `ndigits` wrapping to `0xFFFFFFFF` is a wild store roughly 32 GB past the destination buffer, followed by a multi-billion-iteration out-of-bounds write loop — an out-of-bounds write primitive that scores High.\nA:H - The runaway `ecc_swap_digits()` loop writes over arbitrary kernel memory and will immediately fault or panic the machine, and the corrupted crypto state renders the affected path unusable." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "crypto/ecc.c", "crypto/ecdsa-p1363.c", "crypto/ecdsa-x962.c", "include/linux/math.h" ], "versions": [ { "version": "55779f26eab9af12474a447001bd17070f055712", "lessThan": "f02f0218be412cff1c844addf58e002071be298b", "status": "affected", "versionType": "git" }, { "version": "c6ab5c915da460c0397960af3c308386c3f3247b", "lessThan": "f2133b849ff273abddb6da622daddd8f6f6fa448", "status": "affected", "versionType": "git" }, { "version": "c6ab5c915da460c0397960af3c308386c3f3247b", "lessThan": "921b8167f10708e38080f84e195cdc68a7a561f1", "status": "affected", "versionType": "git" }, { "version": "c6ab5c915da460c0397960af3c308386c3f3247b", "lessThan": "b16510a530d1e6ab9683f04f8fb34f2e0f538275", "status": "affected", "versionType": "git" }, { "version": "6.6.70", "lessThan": "6.6.99", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "crypto/ecc.c", "crypto/ecdsa-p1363.c", "crypto/ecdsa-x962.c", "include/linux/math.h" ], "versions": [ { "version": "6.10", "status": "affected" }, { "version": "0", "lessThan": "6.10", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.99", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.39", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.14.5", "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": "6.6.70", "versionEndExcluding": "6.6.99" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.10", "versionEndExcluding": "6.12.39" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.10", "versionEndExcluding": "6.14.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.10", "versionEndExcluding": "6.15" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/f02f0218be412cff1c844addf58e002071be298b" }, { "url": "https://git.kernel.org/stable/c/f2133b849ff273abddb6da622daddd8f6f6fa448" }, { "url": "https://git.kernel.org/stable/c/921b8167f10708e38080f84e195cdc68a7a561f1" }, { "url": "https://git.kernel.org/stable/c/b16510a530d1e6ab9683f04f8fb34f2e0f538275" } ], "title": "crypto: ecdsa - Harden against integer overflows in DIV_ROUND_UP()", "x_generator": { "engine": "bippy-1.2.0" } } } }