On Mon, 2018-10-15 at 16:02 +0200, Roger Pau Monné wrote:

quoted

This results in a NULL pointer BUG when blkfront_remove and
blkif_free
try to access the failing device's NULL struct blkfront_info.

I guess this is a candidate for backporting?

yes, I think so. At least for kernels >=4.5, which could face this
issue due to commit c31ecf6c12 (this frees the struct blkinfo in the
failing path of talk_to_blkback).

thanks, 

- Vasilis