Bug 2467114 (CVE-2026-43173)

Summary: CVE-2026-43173 kernel: net: ethernet: xscale: Check for PTP support properly
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in the Linux kernel. A local user can trigger a NULL pointer dereference in the `ixp4xx_get_ts_info()` function within the network ethernet xscale driver. This occurs because `ixp46x_ptp_find()` is unconditionally called, even on systems that do not support the ixp46x PTP feature. Successful exploitation of this vulnerability leads to a kernel crash, resulting in a Denial of Service (DoS).
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-05-06 13:05:01 UTC 
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.
Comment 1 Keith Grant 2026-05-06 19:58:57 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026050636-CVE-2026-43173-a8ba@gregkh/T