CVE-2025-38491 mptcp: make fallback action and fallback decision atomic

In the Linux kernel, the following vulnerability has been resolved: mptcp: make fallback action and fallback decision atomic Syzkaller reported the following splat: WARNING: CPU: 1 PID: 7704 at net/mptcp/protocol.h:1223 mptcpdofallback net/mptcp/protocol.h:1223 inline WARNING: CPU: 1 PID: 7704 at...