[SRU][N][PATCH 0/1] CVE-2026-43197

[Cengiz Can]

https://ubuntu.com/security/CVE-2026-43197

[ Impact ]

The msg buffer passed to netconsole from the console subsystem is not
guaranteed to be nul-terminated. After the conversion to the NBCON console
infrastructure, the message is placed in a dynamically allocated per-console
buffer rather than a static global buffer, exposing an out-of-bounds read when
netconsole_write() processes the message via vsnprintf(). An attacker or normal
console activity can trigger a slab-out-of-bounds read past the allocated
region, leading to information disclosure or a kernel crash.

[ Fix ]

noble: backported with AI-assisted adaptation

[ Test Plan ]

Boot tested.

[ Where Problems Could Occur ]

If the fix is incorrect, the netconsole subsystem could truncate or mangle log
messages sent over the network, or fail to properly bound the message length,
potentially regressing remote kernel logging for users who rely on netconsole.