4.14-stable review patch. If anyone has any objections, please let me know.
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From: Eric Biggers ebiggers@google.com
commit 12455e320e19e9cc7ad97f4ab89c280fe297387c upstream.
The arm64 NEON bit-sliced implementation of AES-CTR fails the improved skcipher tests because it sometimes produces the wrong ciphertext. The bug is that the final keystream block isn't returned from the assembly code when the number of non-final blocks is zero. This can happen if the input data ends a few bytes after a page boundary. In this case the last bytes get "encrypted" by XOR'ing them with uninitialized memory.
Fix the assembly code to return the final keystream block when needed.
Fixes: 88a3f582bea9 ("crypto: arm64/aes - don't use IV buffer to return final keystream block") Cc: stable@vger.kernel.org # v4.11+ Reviewed-by: Ard Biesheuvel ard.biesheuvel@linaro.org Signed-off-by: Eric Biggers ebiggers@google.com Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/arm64/crypto/aes-neonbs-core.S | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
--- a/arch/arm64/crypto/aes-neonbs-core.S +++ b/arch/arm64/crypto/aes-neonbs-core.S @@ -940,7 +940,7 @@ CPU_LE( rev x8, x8 ) 8: next_ctr v0 cbnz x4, 99b
-0: st1 {v0.16b}, [x5] + st1 {v0.16b}, [x5] ldp x29, x30, [sp], #16 ret
@@ -948,6 +948,9 @@ CPU_LE( rev x8, x8 ) * If we are handling the tail of the input (x6 != NULL), return the * final keystream block back to the caller. */ +0: cbz x6, 8b + st1 {v0.16b}, [x6] + b 8b 1: cbz x6, 8b st1 {v1.16b}, [x6] b 8b