CVE-2025-40255 - net: core: prevent NULL deref in generic_hwtstamp_ioctl_lower()

CVE ID : CVE-2025-40255 Published : Dec. 4, 2025, 4:16 p.m. | 32 minutes ago Description : In the Linux kernel, the following vulnerability has been resolved: net: core: prevent NULL deref in generic_hwtstamp_ioctl_lower() The ethtool tsconfig Netlink path can trigger a null pointer dereference. A call chain such as: tsconfig_prepare_data() -> dev_get_hwtstamp_phylib() -> vlan_hwtstamp_get() -> generic_hwtstamp_get_lower() -> generic_hwtstamp_ioctl_lower() results in generic_hwtstamp_ioctl_lower() being called with kernel_cfg->ifr as NULL. The generic_hwtstamp_ioctl_lower() function does not expect a NULL ifr and dereferences it, leading to a system crash. Fix this by adding a NULL check for kernel_cfg->ifr in generic_hwtstamp_ioctl_lower(). If ifr is NULL, return -EINVAL. Severity: 0.0 | NA Visit the link for more details, such as CVSS details, affected products, timeline, and more...

Source: Telegram CVE Monitor