CVE-2026-46132 — net: rtnetlink: zero ifla_vf_broadcast to avoid stack infoleak in rtnl_fill_vfinfo

Affected: Linux, Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP, Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP, Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP

In the Linux kernel, the following vulnerability has been resolved:

net: rtnetlink: zero ifla_vf_broadcast to avoid stack infoleak in rtnl_fill_vfinfo

rtnl_fill_vfinfo() declares struct ifla_vf_broadcast on the stack without initialisation:

struct ifla_vf_broadcast vf_broadcast;

The struct contains a single fixed 32-byte field:

/* include/uapi/linux/if_link.h */ struct ifla_vf_broadcast { __u8 broadcast[32]; };

The function then copies dev->broadcast into it using dev->addr_len as the length:

memcpy(vf_broadcast.broadcast, dev->broadcast, dev->addr_len);

On Ethernet devices (the overwhelming majority of SR-IOV NICs) dev->addr_len is 6, so only the first 6 bytes of broadcast[] are written. The remaining 26 bytes retain whatever was previously on the kernel stack. The full struct is then handed to userspace via:

nla_put(skb, IFLA_VF_BROADCAST, sizeof(vf_broadcast), &vf_broadcast)

leaking up to 26 bytes of uninitialised kernel stack per VF per RTM_GETLINK request, repeatable.

The other vf_* structs in the same function are explicitly zeroed for exactly this reason - see the memset() calls for ivi, vf_vlan_info, node_guid and port_guid a few lines above. vf_broadcast was simply missed when it was added.

Reachability: any unprivileged local process can open AF_NETLINK / NETLINK_ROUTE without capabilities and send RTM_GETLINK with an IFLA_EXT_MASK attribute carrying RTEXT_FILTER_VF. The kernel walks each VF and emits IFLA_VF_BROADCAST, leaking 26 bytes of sta…

USN-8566-1 — linux, linux-gcp, linux-gke, linux-realtime vulnerabilities

Affected: Ubuntu:26.04:LTS: linux, Ubuntu:26.04:LTS: linux-gcp, Ubuntu:26.04:LTS: linux-gke, Ubuntu:26.04:LTS: linux-realtime

It was discovered that some AMD Zen 2 processors did not properly isolate shared resources in the operation cache. A local attacker could possibly use this issue to corrupt instructions executed at a higher privilege level, resulting in privilege escalation. (CVE-2025-54518)

Several security issues were discovered in the Linux kernel. An attacker could possibly use these to compromise the system. This update corrects flaws in the following subsystems: - PSP security protocol; - ARM64 architecture; - PowerPC architecture; - RISC-V architecture; - S390 architecture; - User-Mode Linux (UML); - x86 architecture; - Block layer subsystem; - Cryptographic API; - Intel NPU Driver; - DRBD Distributed Replicated Block Device drivers; - Ublk userspace block driver; - Bluetooth drivers; - Bus devices; - Character device driver; - Clock framework and drivers; - CPU frequency scaling framework; - Hardware crypto device drivers; - EDAC drivers; - EFI core; - FWCTL subsystem; - GPU drivers; - HID subsystem; - I3C subsystem; - InfiniBand drivers; - IOMMU subsystem; - Mailbox framework; - Multiple devices driver; - Media drivers; - NVIDIA Tegra memory controller driver; - MTD block device drivers; - Network drivers; - Ethernet bonding driver; - Mellanox network drivers; - Microsoft Azure Network Adapter (MANA) driver; - STMicroelectronics network drivers; - MediaTek network drivers; - NVME drivers; - PCI subsystem;…

Most recent entries from all

CVE-2026-46132 — net: rtnetlink: zero ifla_vf_broadcast to avoid stack infoleak in rtnl_fill_vfinfo

USN-8566-1 — linux, linux-gcp, linux-gke, linux-realtime vulnerabilities