[PATCH 4.19 136/280] crypto: arm64/aes-ccm - fix bugs in non-NEON fallback routine

From: Greg Kroah-Hartman
Date: Fri Mar 22 2019 - 08:03:18 EST


4.19-stable review patch. If anyone has any objections, please let me know.

------------------

From: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>

commit 969e2f59d589c15f6aaf306e590dde16f12ea4b3 upstream.

Commit 5092fcf34908 ("crypto: arm64/aes-ce-ccm: add non-SIMD generic
fallback") introduced C fallback code to replace the NEON routines
when invoked from a context where the NEON is not available (i.e.,
from the context of a softirq taken while the NEON is already being
used in kernel process context)

Fix two logical flaws in the MAC calculation of the associated data.

Reported-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Fixes: 5092fcf34908 ("crypto: arm64/aes-ce-ccm: add non-SIMD generic fallback")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/arm64/crypto/aes-ce-ccm-glue.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

--- a/arch/arm64/crypto/aes-ce-ccm-glue.c
+++ b/arch/arm64/crypto/aes-ce-ccm-glue.c
@@ -125,7 +125,7 @@ static void ccm_update_mac(struct crypto
abytes -= added;
}

- while (abytes > AES_BLOCK_SIZE) {
+ while (abytes >= AES_BLOCK_SIZE) {
__aes_arm64_encrypt(key->key_enc, mac, mac,
num_rounds(key));
crypto_xor(mac, in, AES_BLOCK_SIZE);
@@ -139,8 +139,6 @@ static void ccm_update_mac(struct crypto
num_rounds(key));
crypto_xor(mac, in, abytes);
*macp = abytes;
- } else {
- *macp = 0;
}
}
}