fscrypt: stop pretending that key setup is nofs-safe
fscrypt_get_encryption_info() has never actually been safe to call in a
context that needs GFP_NOFS, since it calls crypto_alloc_skcipher().
crypto_alloc_skcipher() isn't GFP_NOFS-safe, even if called under
memalloc_nofs_save(). This is because it may load kernel modules, and
also because it internally takes crypto_alg_sem. Other tasks can do
GFP_KERNEL allocations while holding crypto_alg_sem for write.
The use of fscrypt_init_mutex isn't GFP_NOFS-safe either.
So, stop pretending that fscrypt_get_encryption_info() is nofs-safe.
I.e., when it allocates memory, just use GFP_KERNEL instead of GFP_NOFS.
Note, another reason to do this is that GFP_NOFS is deprecated in favor
of using memalloc_nofs_save() in the proper places.
Acked-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/20200917041136.178600-10-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
3 files changed