Packet corruption during download, then ffmpeg hangs
Don't drop the "corrupt" packets.
Within HLS input consisting of MPEG-TS segments, each media packet consists of a continuity counter. The CC of the initial packet of a segment is supposed to follow on from the last packet of the prior segment. Some HLS packagers, including ffmpeg, reset these CC across segments (limitation rather than choice).
When demuxing, the HLS packager presents the concatenated media as a single stream and the child MPEG-TS demuxer expects the CC to remain continuous, which it isn't, so it flags it as corrupt. Nothing wrong with the actual media data.