queue-4.14/crypto-arm64-aes-ccm-fix-logical-bug-in-aad-mac-handling.patch

   1 From eaf46edf6ea89675bd36245369c8de5063a0272c Mon Sep 17 00:00:00 2001
   2 From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
   3 Date: Thu, 24 Jan 2019 17:33:45 +0100
   4 Subject: crypto: arm64/aes-ccm - fix logical bug in AAD MAC handling
   5
   6 From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
   7
   8 commit eaf46edf6ea89675bd36245369c8de5063a0272c upstream.
   9
  10 The NEON MAC calculation routine fails to handle the case correctly
  11 where there is some data in the buffer, and the input fills it up
  12 exactly. In this case, we enter the loop at the end with w8 == 0,
  13 while a negative value is assumed, and so the loop carries on until
  14 the increment of the 32-bit counter wraps around, which is quite
  15 obviously wrong.
  16
  17 So omit the loop altogether in this case, and exit right away.
  18
  19 Reported-by: Eric Biggers <ebiggers@kernel.org>
  20 Fixes: a3fd82105b9d1 ("arm64/crypto: AES in CCM mode using ARMv8 Crypto ...")
  21 Cc: stable@vger.kernel.org
  22 Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
  23 Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
  24 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  25
  26 ---
  27  arch/arm64/crypto/aes-ce-ccm-core.S |    5 +++--
  28  1 file changed, 3 insertions(+), 2 deletions(-)
  29
  30 --- a/arch/arm64/crypto/aes-ce-ccm-core.S
  31 +++ b/arch/arm64/crypto/aes-ce-ccm-core.S
  32 @@ -74,12 +74,13 @@ ENTRY(ce_aes_ccm_auth_data)
  33         beq     10f
  34         ext     v0.16b, v0.16b, v0.16b, #1      /* rotate out the mac bytes */
  35         b       7b
  36 -8:     mov     w7, w8
  37 +8:     cbz     w8, 91f
  38 +       mov     w7, w8
  39         add     w8, w8, #16
  40  9:     ext     v1.16b, v1.16b, v1.16b, #1
  41         adds    w7, w7, #1
  42         bne     9b
  43 -       eor     v0.16b, v0.16b, v1.16b
  44 +91:    eor     v0.16b, v0.16b, v1.16b
  45         st1     {v0.16b}, [x0]
  46  10:    str     w8, [x3]
  47         ret