Pull keyrings fixes from David Howells:
"Here's a couple of patches that fix a circular dependency between
holding key->sem and mm->mmap_sem when reading data from a key.
One potential issue is that a filesystem looking to use a key inside,
say, ->readpages() could deadlock if the key being read is the key
that's required and the buffer the key is being read into is on a page
that needs to be fetched.
The case actually detected is a bit more involved - with a filesystem
calling request_key() and locking the target keyring for write - which
could be being read"
* tag 'keys-fixes-20200329' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
KEYS: Avoid false positive ENOMEM error on key read
KEYS: Don't write out to userspace while holding key semaphore
4c205c84e2