tipc: prevent snt_unacked underflow on CONN_ACK

These records connect through source-stated identifiers. Shared identifiers or dates alone do not establish shared exposure, root cause or applicability.

CVE-2026-74282 · Microsoft / collected KEV context

cve-program · CVE-2026-74282

• https://git.kernel.org/stable/c/3388145d258cf2c4c98278e3987296007d30672e
• https://git.kernel.org/stable/c/67e55b054bf8025658dc0e255057f2a6236416bd
• https://git.kernel.org/stable/c/96f91b8ae1a489b3eca137e7acf42cf985fb8939
• https://git.kernel.org/stable/c/47ed873e4ceda34098bd46d8e96b4bb13cad3a04
• https://git.kernel.org/stable/c/b44bebdd32c9ff66ee2aebfc317ced44bedd9335
• https://git.kernel.org/stable/c/3cfa3d8e0dc167850edeb5bf5a07757db83fd54e
• https://git.kernel.org/stable/c/1e2c956745777e6ffdee7f30da5935741c03ee1e
• https://git.kernel.org/stable/c/ab3e10b44ba5411779aac7afd2477917dd77750f

No related operational record is retained in the current change model.