“Both formerly and now, it is only suffering that I describe, and the cessation of suffering.”
The Buddha (from the Sutta Nipata)
This is a saying from the Pali canon, upadhi dukkhassa mūlanti, which means “Attachment is the root of suffering.” So this is a genuine canonical quote.
You’ll find it in this sutta, but translated by Thanissaro as “Acquisition is the root of stress.” His translations are rather idiosyncratic.
In this translation of the same sutta it’s “acquisition is the root of suffering.”
Bhikkhu Bodhi’s translation (not available online, but in The Middle Length Discourses of the Buddha, page 868) has “attachment is the root of suffering,” although he sometimes has “acquisition” in place of “attachment,” in various repetitions of the phrase.
“‘All conditioned things are impermanent’ — when one sees this with wisdom, one turns away from suffering.” The Buddha
This is a genuine Buddha quote. It’s from the Dhammapada, verse 277.