Belated response on this - I was out last week. On Mon, Apr 11, 2022 at 05:37:24PM +0000, Eric Biggers wrote: > On Sun, Apr 10, 2022 at 08:47:05PM +0100, Giovanni Cabiddu wrote: > > If requests exceed 4 entries buffers, memory is allocated dynamically. > > > > In addition, remove the CRYPTO_ALG_ALLOCATES_MEMORY flag from both aead > > and skcipher alg structures. > > > > There is nothing that says that algorithms can ignore > !CRYPTO_ALG_ALLOCATES_MEMORY if there are too many scatterlist entries. See > the > comment above the definition of CRYPTO_ALG_ALLOCATES_MEMORY. >From the conversation in [1], I assumed that a cap on the number of pre-allocated entries in the scatterlists was already agreed.
> If you need to introduce this constraint, then you will need to audit the > users > of !CRYPTO_ALG_ALLOCATES_MEMORY to verify that none of them are issuing > requests > that violate this constraint, then add this to the documentation comment for > CRYPTO_ALG_ALLOCATES_MEMORY. Makes sense. I see that the only users of !CRYPTO_ALG_ALLOCATES_MEMORY are dm-crypt and dm-integrity but I haven't done an audit on those yet to understand if they use more than 4 entries. Regards, [1] https://lore.kernel.org/linux-crypto/[email protected]/ -- Giovanni -- dm-devel mailing list [email protected] https://listman.redhat.com/mailman/listinfo/dm-devel
