{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-40043", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T07:20:57.154Z", "datePublished": "2025-10-28T11:48:22.230Z", "dateUpdated": "2026-08-05T12:07:16.234Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:07:16.234Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: nfc: nci: Add parameter validation for packet data\n\nSyzbot reported an uninitialized value bug in nci_init_req, which was\nintroduced by commit 5aca7966d2a7 (\"Merge tag\n'perf-tools-fixes-for-v6.17-2025-09-16' of\ngit://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools\").\n\nThis bug arises due to very limited and poor input validation\nthat was done at nic_valid_size(). This validation only\nvalidates the skb->len (directly reflects size provided at the\nuserspace interface) with the length provided in the buffer\nitself (interpreted as NCI_HEADER). This leads to the processing\nof memory content at the address assuming the correct layout\nper what opcode requires there. This leads to the accesses to\nbuffer of `skb_buff->data` which is not assigned anything yet.\n\nFollowing the same silent drop of packets of invalid sizes at\n`nic_valid_size()`, add validation of the data in the respective\nhandlers and return error values in case of failure. Release\nthe skb if error values are returned from handlers in\n`nci_nft_packet` and effectively do a silent drop\n\nPossible TODO: because we silently drop the packets, the\ncall to `nci_request` will be waiting for completion of request\nand will face timeouts. These timeouts can get excessively logged\nin the dmesg. A proper handling of them may require to export\n`nci_request_cancel` (or propagate error handling from the\nnft packets handlers)." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:A - The parsed data is NCI notification payload whose RF-specific and activation parameters (ATS/RATS length byte, ATR_RES length, tech-specific params) originate from the contactless peer, so an attacker with a spoofed card or NFC emulator in proximity of a phone/POS/embedded reader supplies the malformed lengths. NFC proximity is Adjacent per kernel scoring guidance (a local unprivileged N_NCI-ldisc path also exists, but is strictly lower severity).\nAC:L - The attacker directly controls the length byte versus actual payload length and can present the malformed card/frame repeatedly until the target polls it; no race, no unpredictable memory-layout precondition is required.\nPR:N - No credentials or account on the target are needed — NFC polling activates and parses the notification automatically, and on the local variant `NCIUARTSETDRIVER` in nci_uart_tty_ioctl() has no capability check at all.\nUI:N - The NFC stack polls and processes discovery/activation notifications autonomously; the attacker brings the hostile device into range and the victim performs no action.\nS:U - The over-read, the write-back in the credits handler, and the leaked data all stay within the kernel's own security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - Tens of bytes past the payload — uninitialized slab tailroom and skb_shared_info, which holds kernel pointers — are copied into nfcid1/sens_res/ATS and exported to userspace via NFC netlink attributes, yielding stale-heap and kernel-pointer disclosure usable for KASLR defeat.\nI:H - `nci_core_conn_credits_ntf_packet()` writes masked bytes back into memory beyond the validated payload for up to 10 entries and adds an out-of-bounds byte into conn_info->credits_cnt, and unvalidated data populates ndev state (nci_ver, manufact_id, remote_gb, credits), giving attacker-shapeable kernel memory/state corruption.\nA:H - Out-of-bounds slab reads can hit a redzone/adjacent object and oops (KASAN/panic_on_oops), and the commit itself notes the resulting dropped packets leave nci_request() blocking until timeout with repeated dmesg flooding, degrading the NFC stack." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/nfc/nci/ntf.c" ], "versions": [ { "version": "6a2968aaf50c7a22fced77a5e24aa636281efca8", "lessThan": "8fcc7315a10a84264e55bb65ede10f0af20a983f", "status": "affected", "versionType": "git" }, { "version": "6a2968aaf50c7a22fced77a5e24aa636281efca8", "lessThan": "bfdda0123dde406dbff62e7e9136037e97998a15", "status": "affected", "versionType": "git" }, { "version": "6a2968aaf50c7a22fced77a5e24aa636281efca8", "lessThan": "0ba68bea1e356f466ad29449938bea12f5f3711f", "status": "affected", "versionType": "git" }, { "version": "6a2968aaf50c7a22fced77a5e24aa636281efca8", "lessThan": "74837bca0748763a77f77db47a0bdbe63b347628", "status": "affected", "versionType": "git" }, { "version": "6a2968aaf50c7a22fced77a5e24aa636281efca8", "lessThan": "c395d1e548cc68e84584ffa2e3ca9796a78bf7b9", "status": "affected", "versionType": "git" }, { "version": "6a2968aaf50c7a22fced77a5e24aa636281efca8", "lessThan": "9c328f54741bd5465ca1dc717c84c04242fac2e1", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/nfc/nci/ntf.c" ], "versions": [ { "version": "3.2", "status": "affected" }, { "version": "0", "lessThan": "3.2", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.195", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.156", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.112", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.53", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.17.3", "lessThanOrEqual": "6.17.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18", "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": "3.2", "versionEndExcluding": "5.15.195" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.2", "versionEndExcluding": "6.1.156" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.2", "versionEndExcluding": "6.6.112" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.2", "versionEndExcluding": "6.12.53" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.2", "versionEndExcluding": "6.17.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.2", "versionEndExcluding": "6.18" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/8fcc7315a10a84264e55bb65ede10f0af20a983f" }, { "url": "https://git.kernel.org/stable/c/bfdda0123dde406dbff62e7e9136037e97998a15" }, { "url": "https://git.kernel.org/stable/c/0ba68bea1e356f466ad29449938bea12f5f3711f" }, { "url": "https://git.kernel.org/stable/c/74837bca0748763a77f77db47a0bdbe63b347628" }, { "url": "https://git.kernel.org/stable/c/c395d1e548cc68e84584ffa2e3ca9796a78bf7b9" }, { "url": "https://git.kernel.org/stable/c/9c328f54741bd5465ca1dc717c84c04242fac2e1" } ], "title": "net: nfc: nci: Add parameter validation for packet data", "x_generator": { "engine": "bippy-1.2.0" } } } }