| Message ID | 20190124163347.12653-2-ard.biesheuvel@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | crypto: arm64/aes-ccm - various bug fixes | expand |
diff --git a/arch/arm64/crypto/aes-ce-ccm-core.S b/arch/arm64/crypto/aes-ce-ccm-core.S index e3a375c4cb83..1b151442dac1 100644 --- 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
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> --- arch/arm64/crypto/aes-ce-ccm-core.S | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) -- 2.20.1