CVE-2026-43094

Description

In the Linux kernel, the following vulnerability has been resolved: ixgbevf: add missing negotiate_features op to Hyper-V ops table Commit a7075f501bd3 ("ixgbevf: fix mailbox API compatibility by negotiating supported features") added the .negotiate_features callback to ixgbe_mac_operations and populated it in ixgbevf_mac_ops, but forgot to add it to ixgbevf_hv_mac_ops. This leaves the function pointer NULL on Hyper-V VMs. During probe, ixgbevf_negotiate_api() calls ixgbevf_set_features(), which unconditionally dereferences hw->mac.ops.negotiate_features(). On Hyper-V this results in a NULL pointer dereference: BUG: kernel NULL pointer dereference, address: 0000000000000000 [...] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine [...] Workqueue: events work_for_cpu_fn RIP: 0010:0x0 [...] Call Trace: ixgbevf_negotiate_api+0x66/0x160 [ixgbevf] ixgbevf_sw_init+0xe4/0x1f0 [ixgbevf] ixgbevf_probe+0x20f/0x4a0 [ixgbevf] local_pci_probe+0x50/0xa0 work_for_cpu_fn+0x1a/0x30 [...] Add ixgbevf_hv_negotiate_features_vf() that returns -EOPNOTSUPP and wire it into ixgbevf_hv_mac_ops. The caller already handles -EOPNOTSUPP gracefully.

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

Linux Kernel (包含commit a7075f501bd3但未应用修复补丁的版本)

PoC / Exploit Code

⚠ For Security Research Only

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

python

/*
 * Conceptual PoC for CVE-2026-43094
 * Trigger: Loading the ixgbevf driver on a Hyper-V VM running a vulnerable kernel.
 * The crash occurs automatically during driver initialization (probe).
 */

#include <linux/module.h>
#include <linux/kernel.h>

// This simulates the missing function pointer in the Hyper-V ops table
// In the vulnerable code, hw->mac.ops.negotiate_features is NULL.

void simulated_trigger(void) {
    // The vulnerability is a NULL pointer dereference.
    // Real exploit: Just load the module 'ixgbevf'.
    void (*null_func)(void) = NULL;
    
    printk(KERN_INFO "Attempting to trigger NULL pointer dereference...\n");
    
    // This line causes the Kernel Panic/Oops in the vulnerable scenario
    // null_func(); 
    
    // Note: Actual exploitation requires the hardware environment (Hyper-V)
    // and the vulnerable kernel version. The crash happens in ixgbevf_negotiate_api.
}

int init_module(void) {
    simulated_trigger();
    return 0;
}

void cleanup_module(void) {
    printk(KERN_INFO "Module unloaded\n");
}

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-43094
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-43094
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-43094/
[4] VulDB https://vuldb.com/cve/CVE-2026-43094
[5] https://git.kernel.org/stable/c/1455ff8809843e6e83f1f5b5c0bcc2224c99a3cb
[6] https://git.kernel.org/stable/c/2270ebab53128fb73c4a70a292be09094074737f
[7] https://git.kernel.org/stable/c/4821d563cd7f251ae728be1a6d04af82a294a5b9
[8] https://git.kernel.org/stable/c/4db7b61ec1d1b2b67c0881b62fc4f9583bc21484
[9] https://git.kernel.org/stable/c/d8a747057a17ffc79e31df1abb11d05e1669d8e5

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-43094", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-06T10:16:22.790", "lastModified": "2026-05-19T20:38:59.263", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nixgbevf: add missing negotiate_features op to Hyper-V ops table\n\nCommit a7075f501bd3 (\"ixgbevf: fix mailbox API compatibility by\nnegotiating supported features\") added the .negotiate_features callback\nto ixgbe_mac_operations and populated it in ixgbevf_mac_ops, but forgot\nto add it to ixgbevf_hv_mac_ops. This leaves the function pointer NULL\non Hyper-V VMs.\n\nDuring probe, ixgbevf_negotiate_api() calls ixgbevf_set_features(),\nwhich unconditionally dereferences hw->mac.ops.negotiate_features().\nOn Hyper-V this results in a NULL pointer dereference:\n\n BUG: kernel NULL pointer dereference, address: 0000000000000000\n [...]\n Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine [...]\n Workqueue: events work_for_cpu_fn\n RIP: 0010:0x0\n [...]\n Call Trace:\n ixgbevf_negotiate_api+0x66/0x160 [ixgbevf]\n ixgbevf_sw_init+0xe4/0x1f0 [ixgbevf]\n ixgbevf_probe+0x20f/0x4a0 [ixgbevf]\n local_pci_probe+0x50/0xa0\n work_for_cpu_fn+0x1a/0x30\n [...]\n\nAdd ixgbevf_hv_negotiate_features_vf() that returns -EOPNOTSUPP and\nwire it into ixgbevf_hv_mac_ops. The caller already handles -EOPNOTSUPP\ngracefully."}], "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": "6.1.158", "versionEndExcluding": "6.2", "matchCriteriaId": "269CADBB-7B11-43CF-9BF8-954B5BBE3FC9"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6.114", "versionEndExcluding": "6.6.136", "matchCriteriaId": "3B4693AB-5652-430E-AA6D-D6005BC338E1"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12.55", "versionEndExcluding": "6.12.83", "matchCriteriaId": "BC685D6B-EAAE-4AB3-B934-49C67FD3333D"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.17.5", "versionEndExcluding": "6.18", "matchCriteriaId": "27929282-2519-484B-B04C-5B62B31FBC5E"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.18.1", "versionEndExcluding": "6.18.24", "matchCriteriaId": "A96857B3-E61E-41C6-AEFD-BCF93E7D64AC"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.14", "matchCriteriaId": "D6A8A074-BBF4-4803-ABED-519A839435BB"}, {"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:6.18:rc2:*:*:*:*:*:*", "matchCriteriaId": "A8A65C5A-918F-4E0B-8E98-08A29FFBA58A"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:6.18:rc3:*:*:*:*:*:*", "matchCriteriaId": "26CA425A-E44F-49D2-92D9-1DDD56398440"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:6.18:rc4:*:*:*:*:*:*", "matchCriteriaId": "BEEBB43A-4C9F-46BE-AA6D-9DBFD2244E55"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:6.18:rc5:*:*:*:*:*:*", "matchCriteriaId": "2545FB83-C4A6-4F62-9ED1-09F75D2E3C78"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:6.18:rc6:*:*:*:*:*:*", "matchCriteriaId": "E955EC5D-4684-4B5D-AE4D-F2BF9ADDBA1D"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:6.18:rc7:*:*:*:*:*:*", "matchCriteriaId": "38C4D89F-9A13-4D29-8645-C9785C142C07"}, {"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-47 ... 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