Eric Biggers 2eb27c1193 crypto: algapi - add NEED_FALLBACK to INHERITED_FLAGS ...

CRYPTO_ALG_NEED_FALLBACK is handled inconsistently.  When it's requested
to be clear, some templates propagate that request to child algorithms,
while others don't.

It's apparently desired for NEED_FALLBACK to be propagated, to avoid
deadlocks where a module tries to load itself while it's being
initialized, and to avoid unnecessarily complex fallback chains where we
have e.g. cbc-aes-$driver falling back to cbc(aes-$driver) where
aes-$driver itself falls back to aes-generic, instead of cbc-aes-$driver
simply falling back to cbc(aes-generic).  There have been a number of
fixes to this effect:

commit 89027579bc ("crypto: xts - Propagate NEED_FALLBACK bit")
commit d2c2a85cfe ("crypto: ctr - Propagate NEED_FALLBACK bit")
commit e6c2e65c70 ("crypto: cbc - Propagate NEED_FALLBACK bit")

But it seems that other templates can have the same problems too.

To avoid this whack-a-mole, just add NEED_FALLBACK to INHERITED_FLAGS so
that it's always inherited.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

2020-07-16 21:49:08 +10:00

9.5 KiB

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