None of those commits are signed. Apparently people on GitHub can commit as torvalds if the author email matches his: https://github.com/amoffat/masquerade/comm

None of those commits are signed. Apparently people on GitHub can commit as torvalds if the author email matches his: https://github.com/amoffat/masquerade/commit/9b0562595cc479ac8696110cb0a2d33f8f2b7d29 https://github.com/amoffat/masquerade/commit/9b0562595cc479a... (You can't fake a fork without hacking the torvalds account, though, so maybe it really was him.)