{"cve":"CVE-2025-71128","nvd":{"published":"2026-01-14T15:16:02.547","modified":"2026-10-19T19:17:14.537","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nerspan: Initialize options_len before referencing options.\n\nThe struct ip_tunnel_info has a flexible array member named\noptions that is protected by a counted_by(options_len)\nattribute.\n\nThe compiler will use this information to enforce runtime bounds\nchecking deployed by FORTIFY_SOURCE string helpers.\n\nAs laid out in the GCC documentation, the counter must be\ninitialized before the first reference to the flexible array\nmember.\n\nAfter scanning through the files that use struct ip_tunnel_info\nand also refer to options or options_len, it appears the normal\ncase is to use the ip_tunnel_info_opts_set() helper.\n\nSaid helper would initialize options_len properly before copying\ndata into options, however in the GRE ERSPAN code a partial\nupdate is done, preventing the use of the helper function.\n\nBefore this change the handling of ERSPAN traffic in GRE tunnels\nwould cause a kernel panic when the kernel is compiled with\nGCC 15+ and having FORTIFY_SOURCE configured:\n\nmemcpy: detected buffer overflow: 4 byte write of buffer size 0\n\nCall Trace:\n <IRQ>\n __fortify_panic+0xd/0xf\n erspan_rcv.cold+0x68/0x83\n ? ip_route_input_slow+0x816/0x9d0\n gre_rcv+0x1b2/0x1c0\n gre_rcv+0x8e/0x100\n ? raw_v4_input+0x2a0/0x2b0\n ip_protocol_deliver_rcu+0x1ea/0x210\n ip_local_deliver_finish+0x86/0x110\n ip_local_deliver+0x65/0x110\n ? ip_rcv_finish_core+0xd6/0x360\n ip_rcv+0x186/0x1a0\n\nReported-at: https://launchpad.net/bugs/2129580","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-665"],"references":["https://git.kernel.org/stable/c/35ddf66c65eff93fff91406756ba273600bf61a3","https://git.kernel.org/stable/c/b282b2a9eed848587c1348abdd5d83fa346a2743"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-21T03:43:09.190223697+00:00"},"epss":{"cve":"CVE-2025-71128","score":0.00309,"percentile":0.23458,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}