CVE-2026-74282

Description

In the Linux kernel, the following vulnerability has been resolved: tipc: prevent snt_unacked underflow on CONN_ACK tipc_sk_conn_proto_rcv() subtracts the peer-supplied connection ack count from the unsigned 16-bit send counter snt_unacked without checking that it does not exceed the number of messages actually outstanding: tsk->snt_unacked -= msg_conn_ack(hdr); msg_conn_ack() is read straight from a received CONN_MANAGER/CONN_ACK message. If the ack count is larger than snt_unacked, the subtraction wraps to a near-maximum value, leaving tsk_conn_cong() permanently true and starving the connection of further transmits. Validate the ACK count at the start of the CONN_ACK block and drop the message if it acknowledges more messages than are outstanding. A peer (or, for a local connection, the connected peer socket) can otherwise wedge a TIPC connection's send side by sending an oversized connection ack.

References

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