The primary vulnerable function 'set_ext_ctrl' was identified directly from the vulnerability description and the ASAN report in the spinics.net mailing list. The other functions ('conf_opt', 'conf_rsp', 'l2cap_parse') are identified from the ASAN stack trace as being part of the execution path that leads to the exploitation of the vulnerability in 'set_ext_ctrl'. While these functions themselves might not contain the overflow, they process the input that eventually triggers it. The confidence for 'set_ext_ctrl' is high due to direct evidence. The confidence for the other functions is medium as they are part of the exploit chain but not the direct site of the overflow. No commit information was found to definitively confirm the patch and the exact nature of the fix, so the analysis relies on the provided vulnerability details and the ASAN report.