bcachefs: Fix null deref in bch2_ioctl_read_super

Do not attempt to cleanup the returned value of bch2_device_lookup if
the returned value was an error pointer. We currently check to see if
the returned value is null and run the cleanup otherwise. As a result,
we attempt to run the cleanup on a error pointer.

Signed-off-by: Dan Robertson <dan@dlrobertson.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This commit is contained in:
Dan Robertson 2021-05-12 20:54:37 -04:00 • committed by Kent Overstreet
commit 2b25de552f