CVE-2025-38124 — net: fix udp gso skb_segment after pull from frag_list

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: fix udp gso skb_segment after pull from frag_list

Commit a1e40ac5b5e9 ("net: gso: fix udp gso fraglist segmentation after pull from frag_list") detected invalid geometry in frag_list skbs and redirects them from skb_segment_list to more robust skb_segment. But some packets with modified geometry can also hit bugs in that code. We don't know how many such cases exist. Addressing each one by one also requires touching the complex skb_segment code, which risks introducing bugs for other types of skbs. Instead, linearize all these packets that fail the basic invariants on gso fraglist skbs. That is more robust.

If only part of the fraglist payload is pulled into head_skb, it will always cause exception when splitting skbs by skb_segment. For detailed call stack information, see below.

Valid SKB_GSO_FRAGLIST skbs - consist of two or more segments - the head_skb holds the protocol headers plus first gso_size - one or more frag_list skbs hold exactly one segment - all but the last must be gso_size

Optional datapath hooks such as NAT and BPF (bpf_skb_pull_data) can modify fraglist skbs, breaking these invariants.

In extreme cases they pull one part of data into skb linear. For UDP, this causes three payloads with lengths of (11,11,10) bytes were pulled tail to become (12,10,10) bytes.

The skbs no longer meets the above SKB_GSO_FRAGLIST conditions because payload was pulled into head_skb, it needs to be…

USN-7769-1 — linux, linux-aws, linux-gcp, linux-gcp-6.14, linux-oracle, linux-realtime vulnerabilities

Affected: Ubuntu:24.04:LTS: linux-gcp-6.14

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: - ARM64 architecture; - PowerPC architecture; - x86 architecture; - Block layer subsystem; - Cryptographic API; - ACPI drivers; - Android drivers; - Bluetooth drivers; - Bus devices; - Clock framework and drivers; - CPU frequency scaling framework; - Hardware crypto device drivers; - DMA engine subsystem; - EDAC drivers; - Arm Firmware Framework for ARMv8-A(FFA); - FPGA Framework; - GPIO subsystem; - GPU drivers; - HID subsystem; - Hardware monitoring drivers; - HW tracing; - InfiniBand drivers; - IOMMU subsystem; - Multiple devices driver; - Media drivers; - VMware VMCI Driver; - MTD block device drivers; - Network drivers; - Mellanox network drivers; - STMicroelectronics network drivers; - NVDIMM (Non-Volatile Memory Device) drivers; - NVME drivers; - NVMEM (Non Volatile Memory) drivers; - PCI subsystem; - Amlogic Meson DDR PMU; - NI-700 PMU driver; - PHY drivers; - Pin controllers subsystem; - x86 platform drivers; - PTP clock framework; - SCSI subsystem; - ASPEED SoC drivers; - SPI subsystem; - TCM subsystem; - Thunderbolt and USB4 drivers; - TTY drivers; - UFS subsystem; - USB core drivers; - USB Gadget drivers; - Renesas USBHS Controller drivers; - USB Type-C Port Controller Manager driver;…

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CVE-2025-38124 — net: fix udp gso skb_segment after pull from frag_list

USN-7769-1 — linux, linux-aws, linux-gcp, linux-gcp-6.14, linux-oracle, linux-realtime vulnerabilities