crypto: aesni-intel - fix unaligned cbc decrypt for x86-32

The 32 bit variant of cbc(aes) decrypt is using instructions requiring
128 bit aligned memory locations but fails to ensure this constraint in
the code. Fix this by loading the data into intermediate registers with
load unaligned instructions.

This fixes reported general protection faults related to aesni.

References: https://bugzilla.kernel.org/show_bug.cgi?id=43223
Reported-by: Daniel <garkein@mailueberfall.de>
Cc: stable@kernel.org [v2.6.39+]
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 4 insertions, 2 deletions

diff --git a/arch/x86/crypto/aesni-intel_asm.S b/arch/x86/crypto/aesni-intel_asm.S
index be6d9e365a8..3470624d783 100644
--- a/arch/x86/crypto/aesni-intel_asm.S
+++ b/arch/x86/crypto/aesni-intel_asm.S
@@ -2460,10 +2460,12 @@ ENTRY(aesni_cbc_dec)
         pxor IN3, STATE4
         movaps IN4, IV
 #else
-        pxor (INP), STATE2
-        pxor 0x10(INP), STATE3
         pxor IN1, STATE4
         movaps IN2, IV
+        movups (INP), IN1
+        pxor IN1, STATE2
+        movups 0x10(INP), IN2
+        pxor IN2, STATE3
 #endif
         movups STATE1, (OUTP)
         movups STATE2, 0x10(OUTP)