CVE-2026-43445

Description

In the Linux kernel, the following vulnerability has been resolved: e1000/e1000e: Fix leak in DMA error cleanup If an error is encountered while mapping TX buffers, the driver should unmap any buffers already mapped for that skb. Because count is incremented after a successful mapping, it will always match the correct number of unmappings needed when dma_error is reached. Decrementing count before the while loop in dma_error causes an off-by-one error. If any mapping was successful before an unsuccessful mapping, exactly one DMA mapping would leak. In these commits, a faulty while condition caused an infinite loop in dma_error: Commit 03b1320dfcee ("e1000e: remove use of skb_dma_map from e1000e driver") Commit 602c0554d7b0 ("e1000: remove use of skb_dma_map from e1000 driver") Commit c1fa347f20f1 ("e1000/e1000e/igb/igbvf/ixgb/ixgbe: Fix tests of unsigned in *_tx_map()") fixed the infinite loop, but introduced the off-by-one error. This issue may still exist in the igbvf driver, but I did not address it in this patch.

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 (e1000/e1000e drivers)

PoC / Exploit Code

⚠ For Security Research Only

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

python

/*
 * PoC Concept: Demonstration of the off-by-one logic error in e1000/e1000e driver.
 * This snippet simulates the flawed DMA cleanup logic.
 */

#include <stdio.h>

void vulnerable_cleanup(int mapped_count) {
    // Vulnerable logic: Decrementing count before the loop
    // If mapped_count is 1, count becomes 0, loop doesn't run, 1 buffer leaks.
    int count = mapped_count - 1;

    printf("Buffers to clean: %d\n", mapped_count);

    while (count >= 0) {
        // dma_unmap_single(dev, buffer[count], size, DMA_TO_DEVICE);
        printf("Unmapping buffer index %d\n", count);
        count--;
    }
    printf("Leaked buffers: %d\n", mapped_count - (mapped_count - 1)); // Simplified visualization
}

int main() {
    // Scenario: 1 buffer was mapped successfully, then an error occurred.
    int mapped_buffers = 1;
    printf("Simulating DMA error with %d mapped buffer.\n", mapped_buffers);
    vulnerable_cleanup(mapped_buffers);
    return 0;
}

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-43445
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-43445
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-43445/
[4] VulDB https://vuldb.com/cve/CVE-2026-43445
[5] https://git.kernel.org/stable/c/0606c24a745bafd1be5d66c48361638cd9cad74b
[6] https://git.kernel.org/stable/c/0a1fc25deabab4efce64610e3c449485c4fa8f5f
[7] https://git.kernel.org/stable/c/10b5e65959e955a1c8894e0a5413944b5a70204a
[8] https://git.kernel.org/stable/c/30e87ade8d678c25a8546cf38c0b498fa5cb27d3
[9] https://git.kernel.org/stable/c/519051c711dfd239ef6e4b28878efee400a035f9
[10] https://git.kernel.org/stable/c/7eaeb778bfaa3b2a804f89321c234d59c74569db
[11] https://git.kernel.org/stable/c/e94eaef11142b01f77bf8ba4d0b59720b7858109
[12] https://git.kernel.org/stable/c/fa5ba9867a55e640df0dc79bf0199770fb043f03

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-43445", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-08T15:16:56.983", "lastModified": "2026-05-21T16:38:08.130", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ne1000/e1000e: Fix leak in DMA error cleanup\n\nIf an error is encountered while mapping TX buffers, the driver should\nunmap any buffers already mapped for that skb.\n\nBecause count is incremented after a successful mapping, it will always\nmatch the correct number of unmappings needed when dma_error is reached.\nDecrementing count before the while loop in dma_error causes an\noff-by-one error. If any mapping was successful before an unsuccessful\nmapping, exactly one DMA mapping would leak.\n\nIn these commits, a faulty while condition caused an infinite loop in\ndma_error:\nCommit 03b1320dfcee (\"e1000e: remove use of skb_dma_map from e1000e\ndriver\")\nCommit 602c0554d7b0 (\"e1000: remove use of skb_dma_map from e1000 driver\")\n\nCommit c1fa347f20f1 (\"e1000/e1000e/igb/igbvf/ixgb/ixgbe: Fix tests of\nunsigned in *_tx_map()\") fixed the infinite loop, but introduced the\noff-by-one error.\n\nThis issue may still exist in the igbvf driver, but I did not address it\nin this patch."}], "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-401"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.33.1", "versionEndExcluding": "5.10.253", "matchCriteriaId": "9AAED072-B61B-4439-8F12-1FDA964D59DC"}, {"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": "6.1.167", "matchCriteriaId": "2EDC6BAF-B710-4E26-B6AA-D68922EE7B43"}, {"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": "6.12.78", "matchCriteriaId": "28D591F5-B196-4CC9-905C-DC80F116E7A8"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.19", "matchCriteriaId": "D394AC60-6F28-435F-872A-CCDF384B8331"}, {"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:2.6.33:-:*:*:*:*:*:*", "matchCriteriaId": "EF818826-D9F2-42F9-9638-9609513561A3"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:2.6.33:rc6:*:*:*:*:*:*", "matchCriteriaId": "B220EA3F-55B3-4B6E-8285-B28ADEF50138"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:2.6.33:rc7:*:*:*:*:*:*", "matchCriteriaId": "C61AB348-ACF4-4F88-AC9D-BEC63B76399C"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:2.6.33:rc8:*:*:*:*:*:*", "matchCriteriaId": "C3AFD58E-A261-4398-BA11-B62A091261F6"}, {"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"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/0606c24a745bafd1be5d66c48361638cd9cad74b", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/0a1fc25deabab4efce64610e3c449485c4fa8f5f", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/10b5e65959e955a1c8894e0a5413944b5a70204a", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git ... (truncated)