From: Eric Biggers <ebiggers@xxxxxxxxxx> Upon additional review, the new fast path in adiantum_finish() is missing the call to flush_dcache_page() that scatterwalk_map_and_copy() was doing. It's apparently debatable whether flush_dcache_page() is actually needed, as per the discussion at https://lore.kernel.org/lkml/YYP1lAq46NWzhOf0@xxxxxxxxxxxxxxxxxxxx/T/#u. However, it appears that currently all the helper functions that write to a page, such as scatterwalk_map_and_copy(), memcpy_to_page(), and memzero_page(), do the dcache flush. So do it to be consistent. Fixes: dadf5e56c967 ("crypto: adiantum - add fast path for single-page messages") Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx> --- crypto/adiantum.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/crypto/adiantum.c b/crypto/adiantum.c index 9ff3376f9ed3..60f3883b736a 100644 --- a/crypto/adiantum.c +++ b/crypto/adiantum.c @@ -293,30 +293,32 @@ static int adiantum_finish(struct skcipher_request *req) /* * Second hash step * enc: C_R = C_M - H_{K_H}(T, C_L) * dec: P_R = P_M - H_{K_H}(T, P_L) */ rctx->u.hash_desc.tfm = tctx->hash; le128_sub(&rctx->rbuf.bignum, &rctx->rbuf.bignum, &rctx->header_hash); if (dst_nents == 1 && dst->offset + req->cryptlen <= PAGE_SIZE) { /* Fast path for single-page destination */ - void *virt = kmap_local_page(sg_page(dst)) + dst->offset; + struct page *page = sg_page(dst); + void *virt = kmap_local_page(page) + dst->offset; err = crypto_shash_digest(&rctx->u.hash_desc, virt, bulk_len, (u8 *)&digest); if (err) { kunmap_local(virt); return err; } le128_sub(&rctx->rbuf.bignum, &rctx->rbuf.bignum, &digest); memcpy(virt + bulk_len, &rctx->rbuf.bignum, sizeof(le128)); + flush_dcache_page(page); kunmap_local(virt); } else { /* Slow path that works for any destination scatterlist */ err = adiantum_hash_message(req, dst, dst_nents, &digest); if (err) return err; le128_sub(&rctx->rbuf.bignum, &rctx->rbuf.bignum, &digest); scatterwalk_map_and_copy(&rctx->rbuf.bignum, dst, bulk_len, sizeof(le128), 1); } base-commit: f2b88bab69c86d4dab2bfd25a0e741d7df411f7a -- 2.42.0
