CVE-2026-74282

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux10724cc7bb7832b482df049c20fd824d928c5eaa < 3388145d258cf2c4c98278e3987296007d30672eaffected
LinuxLinux10724cc7bb7832b482df049c20fd824d928c5eaa < 67e55b054bf8025658dc0e255057f2a6236416bdaffected
LinuxLinux10724cc7bb7832b482df049c20fd824d928c5eaa < 96f91b8ae1a489b3eca137e7acf42cf985fb8939affected
LinuxLinux10724cc7bb7832b482df049c20fd824d928c5eaa < 47ed873e4ceda34098bd46d8e96b4bb13cad3a04affected
LinuxLinux10724cc7bb7832b482df049c20fd824d928c5eaa < b44bebdd32c9ff66ee2aebfc317ced44bedd9335affected
LinuxLinux10724cc7bb7832b482df049c20fd824d928c5eaa < 3cfa3d8e0dc167850edeb5bf5a07757db83fd54eaffected
LinuxLinux10724cc7bb7832b482df049c20fd824d928c5eaa < 1e2c956745777e6ffdee7f30da5935741c03ee1eaffected
LinuxLinux10724cc7bb7832b482df049c20fd824d928c5eaa < ab3e10b44ba5411779aac7afd2477917dd77750faffected
LinuxLinux4.7affected
LinuxLinux0 < 4.7unaffected
LinuxLinux5.10.261 <= 5.10.*unaffected
LinuxLinux5.15.212 <= 5.15.*unaffected
LinuxLinux6.1.178 <= 6.1.*unaffected
LinuxLinux6.6.145 <= 6.6.*unaffected
LinuxLinux6.12.97 <= 6.12.*unaffected
LinuxLinux6.18.40 <= 6.18.*unaffected
LinuxLinux7.1.5 <= 7.1.*unaffected
LinuxLinux7.2 <= *unaffected

Weaknesses

References