CVE-2026-43341
In the Linux kernel, the following vulnerability has been resolved: net/ipv6: ioam6: prevent schema length wraparound in trace fill ioam6_fill_trace_data() stores the schema contribution to the trace length in a u8. With bit 22 enabled and the largest schema payload, sclen becomes 1 + 1020 / 4, wraps from 256 to 0, and bypasses the remaining-space check. __ioam6_fill_trace_data() then positions the write cursor without reserving the schema area but still copies the 4-byte schema header and the full schema payload, overrunning the trace buffer. Keep sclen in an unsigned int so the remaining-space check and the write cursor calculation both see the full schema length.
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A critical buffer overflow has been identified in the Linux kernel IPv6 IOAM6 subsystem. An integer wraparound allows an attacker to bypass memory checks, leading to a buffer overrun that could potentially result in remote code execution or a system crash. System administrators and developers running Linux-based infrastructure should verify their kernel versions and apply updates.
Severity
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HEPSS
Technical description
In the Linux kernel, the following vulnerability has been resolved: net/ipv6: ioam6: prevent schema length wraparound in trace fill ioam6_fill_trace_data() stores the schema contribution to the trace length in a u8. With bit 22 enabled and the largest schema payload, sclen becomes 1 + 1020 / 4, wraps from 256 to 0, and bypasses the remaining-space check. __ioam6_fill_trace_data() then positions the write cursor without reserving the schema area but still copies the 4-byte schema header and the full schema payload, overrunning the trace buffer. Keep sclen in an unsigned int so the remaining-space check and the write cursor calculation both see the full schema length.
References
- https://git.kernel.org/stable/c/184d2e9db27c0f76226b5cad16fe29510a5d2280
- https://git.kernel.org/stable/c/5e67ba9bb531e1ec6599a82a065dea9040b9ce50
- https://git.kernel.org/stable/c/77695a69baca9b99d95fad09fc78c2318736604f
- https://git.kernel.org/stable/c/d1b041080086e91d3733a5438a8c51ad5d3d8e09
- https://git.kernel.org/stable/c/d6e1c9b02d85a4f1f4ba6d68e916d9b610a3ed7d
- https://git.kernel.org/stable/c/e96d48b37708d53cbdc47f6f60b0714fc4a5f596