CVE-2026-43173

Description

In the Linux kernel, the following vulnerability has been resolved: net: ethernet: xscale: Check for PTP support properly In ixp4xx_get_ts_info() ixp46x_ptp_find() is called unconditionally despite this feature only existing on ixp46x, leading to the following splat from tcpdump: root@OpenWrt:~# tcpdump -vv -X -i eth0 (...) Unable to handle kernel NULL pointer dereference at virtual address 00000238 when read (...) Call trace: ptp_clock_index from ixp46x_ptp_find+0x1c/0x38 ixp46x_ptp_find from ixp4xx_get_ts_info+0x4c/0x64 ixp4xx_get_ts_info from __ethtool_get_ts_info+0x90/0x108 __ethtool_get_ts_info from __dev_ethtool+0xa00/0x2648 __dev_ethtool from dev_ethtool+0x160/0x234 dev_ethtool from dev_ioctl+0x2cc/0x460 dev_ioctl from sock_ioctl+0x1ec/0x524 sock_ioctl from sys_ioctl+0x51c/0xa94 sys_ioctl from ret_fast_syscall+0x0/0x44 (...) Segmentation fault Check for ixp46x in ixp46x_ptp_find() before trying to set up PTP to avoid this. To avoid altering the returned error code from ixp4xx_hwtstamp_set() which before this patch was -EOPNOTSUPP, we return -EOPNOTSUPP from ixp4xx_hwtstamp_set() if ixp46x_ptp_find() fails no matter the error code. The helper function ixp46x_ptp_find() helper returns -ENODEV.

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 (ixp4xx_eth driver)

PoC / Exploit Code

⚠ For Security Research Only

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

python

#!/bin/bash
# PoC for CVE-2026-43173
# Trigger the NULL pointer dereference by running tcpdump on vulnerable hardware
# Usage: ./poc.sh

tcpdump -vv -X -i eth0

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-43173
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-43173
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-43173/
[4] VulDB https://vuldb.com/cve/CVE-2026-43173
[5] https://git.kernel.org/stable/c/144dde3146985b25fa84d4e4b7c3d11e0f5fc5a4
[6] https://git.kernel.org/stable/c/21d1e80d0d6e7d0c3cd8b1e001ed1fa92fb9f3f5
[7] https://git.kernel.org/stable/c/2d74412dfd3621552a394d55cc3dd26a7cbf608e
[8] https://git.kernel.org/stable/c/322437972f0a712767f6920ad34aba25f2e9b942
[9] https://git.kernel.org/stable/c/5195b10c34b8993194ad12ad7d8f54d861be084b
[10] https://git.kernel.org/stable/c/594163ea88a03bdb412063af50fc7177ef3cbeae
[11] https://git.kernel.org/stable/c/cbecebd35909f6cd0f6fb773f0fb73da99e02f8c

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-43173", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-06T12:16:35.707", "lastModified": "2026-05-12T20:01:45.853", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: ethernet: xscale: Check for PTP support properly\n\nIn ixp4xx_get_ts_info() ixp46x_ptp_find() is called\nunconditionally despite this feature only existing on\nixp46x, leading to the following splat from tcpdump:\n\nroot@OpenWrt:~# tcpdump -vv -X -i eth0\n(...)\nUnable to handle kernel NULL pointer dereference at virtual address\n 00000238 when read\n(...)\nCall trace:\n ptp_clock_index from ixp46x_ptp_find+0x1c/0x38\n ixp46x_ptp_find from ixp4xx_get_ts_info+0x4c/0x64\n ixp4xx_get_ts_info from __ethtool_get_ts_info+0x90/0x108\n __ethtool_get_ts_info from __dev_ethtool+0xa00/0x2648\n __dev_ethtool from dev_ethtool+0x160/0x234\n dev_ethtool from dev_ioctl+0x2cc/0x460\n dev_ioctl from sock_ioctl+0x1ec/0x524\n sock_ioctl from sys_ioctl+0x51c/0xa94\n sys_ioctl from ret_fast_syscall+0x0/0x44\n (...)\nSegmentation fault\n\nCheck for ixp46x in ixp46x_ptp_find() before trying to set up\nPTP to avoid this.\n\nTo avoid altering the returned error code from ixp4xx_hwtstamp_set()\nwhich before this patch was -EOPNOTSUPP, we return -EOPNOTSUPP\nfrom ixp4xx_hwtstamp_set() if ixp46x_ptp_find() fails no matter\nthe error code. The helper function ixp46x_ptp_find() helper\nreturns -ENODEV."}], "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": "5.15", "versionEndExcluding": "5.15.202", "matchCriteriaId": "B0330CE4-09CE-43EF-A9C8-CD49FFD1DC98"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "6.1.165", "matchCriteriaId": "797C7F46-D0BE-4FB8-A502-C5EF8E6B6654"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.6.128", "matchCriteriaId": "851E9353-6C09-4CC9-877E-E09DB164A3C2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.12.75", "matchCriteriaId": "BCE16369-98ED-41CF-8995-DFDC10B288D2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.16", "matchCriteriaId": "B4B8CDA9-BADF-4CF5-8B3B-702DE8EEA40B"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.6", "matchCriteriaId": "373EEEDA-FAA1-4FB4-B6ED-DB4DD99DBE67"}, {"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/144dde3146985b25fa84d4e4b7c3d11e0f5fc5a4", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/21d1e80d0d6e7d0c3cd8b1e001ed1fa92fb9f3f5", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/2d74412dfd3621552a394d55cc3dd26a7cbf608e", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/322437972f0a712767f6920ad34aba25f2e9b942", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/5195b10c34b8993194ad12ad7d8f54d861be084b", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/594163ea88a03bdb412063af50fc7177ef3cbeae", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/cbecebd35909f6cd0f6fb773f0fb73da99e02f8c", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}