also fwiw, confirmed that starting from tag Ubuntu-5.15.0-25.25 (commit f4a9abe17854fc753c84a0ba4ac275e715a008f3), reverting commit 6d7a793aabf31d7ba2b16fc13a94ccf0b90e4be0 applies cleanly and fixes the bug.
also fwiw, confirmed that starting from tag Ubuntu-5.15.0-25.25 (commit f4a9abe17854fc7 53c84a0ba4ac275 e715a008f3) , reverting commit 6d7a793aabf31d7 ba2b16fc13a94cc f0b90e4be0 applies cleanly and fixes the bug.