CVE-2026-43173

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.

Weakness

The product dereferences a pointer that it expects to be valid but is NULL.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/21d1e80d0d6e7d0c3cd8b1e001ed1fa92fb9f3f5
• https://git.kernel.org/stable/c/2d74412dfd3621552a394d55cc3dd26a7cbf608e
• https://git.kernel.org/stable/c/322437972f0a712767f6920ad34aba25f2e9b942
• https://git.kernel.org/stable/c/594163ea88a03bdb412063af50fc7177ef3cbeae
• https://git.kernel.org/stable/c/cbecebd35909f6cd0f6fb773f0fb73da99e02f8c