UBUNTU-CVE-2026-80980: High severity ubuntu/linux-hwe-edge vulnerability
In the Linux kernel, the following vulnerability has been resolved: net/smc: stop killed, freed and outofsync sharing a byte The three connection state flags are single-bit bitfields, so they occupy one byte of struct smcconnection and every store to one is a read-modify-write of the other two: u8 killed : 1; u8 freed : 1; u8 outofsync : 1; They are not written under a common lock. smccdcmsgvalidate() sets outofsync from the receive tasklet, while smcconnkill() sets killed from process context under locksock(), and the receive path does not defer to the backlog when the socket is owned -- smccdcmsgrecv() takes only bhlocksock(). Give each flag its own byte so a store no longer touches its neighbours. All readers test them as booleans and are unchanged. struct smcconnection grows by two bytes.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Compensating control
In the Linux kernel net/smc implementation, give each smc_connection state flag—killed, freed, and out_of_sync—its own byte instead of making them single-bit bitfields, so stores no longer use read-modify-write operations that touch neighboring flags.