6.6-stable review patch. If anyone has any objections, please let me know.
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From: Eric Biggers ebiggers@google.com
[ Upstream commit bb40d32689d73c46de39a0529d551f523f21dc9b ]
Since commit adad556efcdd ("crypto: api - Fix built-in testing dependency failures"), the following warning appears when booting an x86_64 kernel that is configured with CONFIG_CRYPTO_MANAGER_EXTRA_TESTS=y and CONFIG_CRYPTO_AES_NI_INTEL=y, even when CONFIG_CRYPTO_XTS=y and CONFIG_CRYPTO_AES=y:
alg: skcipher: skipping comparison tests for xts-aes-aesni because xts(ecb(aes-generic)) is unavailable
This is caused by an issue in the xts template where it allocates an "aes" single-block cipher without declaring a dependency on it via the crypto_spawn mechanism. This issue was exposed by the above commit because it reversed the order that the algorithms are tested in.
Specifically, when "xts(ecb(aes-generic))" is instantiated and tested during the comparison tests for "xts-aes-aesni", the "xts" template allocates an "aes" crypto_cipher for encrypting tweaks. This resolves to "aes-aesni". (Getting "aes-aesni" instead of "aes-generic" here is a bit weird, but it's apparently intended.) Due to the above-mentioned commit, the testing of "aes-aesni", and the finalization of its registration, now happens at this point instead of before. At the end of that, crypto_remove_spawns() unregisters all algorithm instances that depend on a lower-priority "aes" implementation such as "aes-generic" but that do not depend on "aes-aesni". However, because "xts" does not use the crypto_spawn mechanism for its "aes", its dependency on "aes-aesni" is not recognized by crypto_remove_spawns(). Thus, crypto_remove_spawns() unexpectedly unregisters "xts(ecb(aes-generic))".
Fix this issue by making the "xts" template use the crypto_spawn mechanism for its "aes" dependency, like what other templates do.
Note, this fix could be applied as far back as commit f1c131b45410 ("crypto: xts - Convert to skcipher"). However, the issue only got exposed by the much more recent changes to how the crypto API runs the self-tests, so there should be no need to backport this to very old kernels. Also, an alternative fix would be to flip the list iteration order in crypto_start_tests() to restore the original testing order. I'm thinking we should do that too, since the original order seems more natural, but it shouldn't be relied on for correctness.
Fixes: adad556efcdd ("crypto: api - Fix built-in testing dependency failures") Signed-off-by: Eric Biggers ebiggers@google.com Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: Sasha Levin sashal@kernel.org --- crypto/xts.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-)
diff --git a/crypto/xts.c b/crypto/xts.c index 548b302c6c6a0..038f60dd512d9 100644 --- a/crypto/xts.c +++ b/crypto/xts.c @@ -28,7 +28,7 @@ struct xts_tfm_ctx {
struct xts_instance_ctx { struct crypto_skcipher_spawn spawn; - char name[CRYPTO_MAX_ALG_NAME]; + struct crypto_cipher_spawn tweak_spawn; };
struct xts_request_ctx { @@ -306,7 +306,7 @@ static int xts_init_tfm(struct crypto_skcipher *tfm)
ctx->child = child;
- tweak = crypto_alloc_cipher(ictx->name, 0, 0); + tweak = crypto_spawn_cipher(&ictx->tweak_spawn); if (IS_ERR(tweak)) { crypto_free_skcipher(ctx->child); return PTR_ERR(tweak); @@ -333,11 +333,13 @@ static void xts_free_instance(struct skcipher_instance *inst) struct xts_instance_ctx *ictx = skcipher_instance_ctx(inst);
crypto_drop_skcipher(&ictx->spawn); + crypto_drop_cipher(&ictx->tweak_spawn); kfree(inst); }
static int xts_create(struct crypto_template *tmpl, struct rtattr **tb) { + char name[CRYPTO_MAX_ALG_NAME]; struct skcipher_instance *inst; struct xts_instance_ctx *ctx; struct skcipher_alg *alg; @@ -363,13 +365,13 @@ static int xts_create(struct crypto_template *tmpl, struct rtattr **tb) cipher_name, 0, mask); if (err == -ENOENT) { err = -ENAMETOOLONG; - if (snprintf(ctx->name, CRYPTO_MAX_ALG_NAME, "ecb(%s)", + if (snprintf(name, CRYPTO_MAX_ALG_NAME, "ecb(%s)", cipher_name) >= CRYPTO_MAX_ALG_NAME) goto err_free_inst;
err = crypto_grab_skcipher(&ctx->spawn, skcipher_crypto_instance(inst), - ctx->name, 0, mask); + name, 0, mask); }
if (err) @@ -398,23 +400,28 @@ static int xts_create(struct crypto_template *tmpl, struct rtattr **tb) if (!strncmp(cipher_name, "ecb(", 4)) { int len;
- len = strscpy(ctx->name, cipher_name + 4, sizeof(ctx->name)); + len = strscpy(name, cipher_name + 4, sizeof(name)); if (len < 2) goto err_free_inst;
- if (ctx->name[len - 1] != ')') + if (name[len - 1] != ')') goto err_free_inst;
- ctx->name[len - 1] = 0; + name[len - 1] = 0;
if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, - "xts(%s)", ctx->name) >= CRYPTO_MAX_ALG_NAME) { + "xts(%s)", name) >= CRYPTO_MAX_ALG_NAME) { err = -ENAMETOOLONG; goto err_free_inst; } } else goto err_free_inst;
+ err = crypto_grab_cipher(&ctx->tweak_spawn, + skcipher_crypto_instance(inst), name, 0, mask); + if (err) + goto err_free_inst; + inst->alg.base.cra_priority = alg->base.cra_priority; inst->alg.base.cra_blocksize = XTS_BLOCK_SIZE; inst->alg.base.cra_alignmask = alg->base.cra_alignmask |