CVE-2025-71128

Description

In the Linux kernel, the following vulnerability has been resolved:erspan: Initialize options_len before referencing options.The struct ip_tunnel_info has a flexible array member namedoptions that is protected by a counted_by(options_len)attribute.The compiler will use this information to enforce runtime boundschecking deployed by FORTIFY_SOURCE string helpers.As laid out in the GCC documentation, the counter must beinitialized before the first reference to the flexible arraymember.After scanning through the files that use struct ip_tunnel_infoand also refer to options or options_len, it appears the normalcase is to use the ip_tunnel_info_opts_set() helper.Said helper would initialize options_len properly before copyingdata into options, however in the GRE ERSPAN code a partialupdate is done, preventing the use of the helper function.Before this change the handling of ERSPAN traffic in GRE tunnelswould cause a kernel panic when the kernel is compiled withGCC 15+ and having FORTIFY_SOURCE configured:memcpy: detected buffer overflow: 4 byte write of buffer size 0Call Trace: __fortify_panic+0xd/0xf erspan_rcv.cold+0x68/0x83 ip_route_input_slow+0x816/0x9d0 gre_rcv+0x1b2/0x1c0 gre_rcv+0x8e/0x100 raw_v4_input+0x2a0/0x2b0 ip_protocol_deliver_rcu+0x1ea/0x210 ip_local_deliver_finish+0x86/0x110 ip_local_deliver+0x65/0x110 ip_rcv_finish_core+0xd6/0x360 ip_rcv+0x186/0x1a0Reported-at: https://launchpad.net/bugs/2129580

Risk Information

Associated Vulnerability

Patch Details

References

https://nvd.nist.gov/vuln/detail/CVE-2023-1234
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-1234