3.16.70-rc1 review patch. If anyone has any objections, please let me know.
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From: Ard Biesheuvel ard.biesheuvel@linaro.org
commit eaf46edf6ea89675bd36245369c8de5063a0272c upstream.
The NEON MAC calculation routine fails to handle the case correctly where there is some data in the buffer, and the input fills it up exactly. In this case, we enter the loop at the end with w8 == 0, while a negative value is assumed, and so the loop carries on until the increment of the 32-bit counter wraps around, which is quite obviously wrong.
So omit the loop altogether in this case, and exit right away.
Reported-by: Eric Biggers ebiggers@kernel.org Fixes: a3fd82105b9d1 ("arm64/crypto: AES in CCM mode using ARMv8 Crypto ...") Signed-off-by: Ard Biesheuvel ard.biesheuvel@linaro.org Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: Ben Hutchings ben@decadent.org.uk --- arch/arm64/crypto/aes-ce-ccm-core.S | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
--- a/arch/arm64/crypto/aes-ce-ccm-core.S +++ b/arch/arm64/crypto/aes-ce-ccm-core.S @@ -74,12 +74,13 @@ ENTRY(ce_aes_ccm_auth_data) beq 10f ext v0.16b, v0.16b, v0.16b, #1 /* rotate out the mac bytes */ b 7b -8: mov w7, w8 +8: cbz w8, 91f + mov w7, w8 add w8, w8, #16 9: ext v1.16b, v1.16b, v1.16b, #1 adds w7, w7, #1 bne 9b - eor v0.16b, v0.16b, v1.16b +91: eor v0.16b, v0.16b, v1.16b st1 {v0.16b}, [x0] 10: str w8, [x3] ret