| Message ID | 1473756533-21078-1-git-send-email-ard.biesheuvel@linaro.org |
|---|---|
| State | Accepted |
| Commit | f82e90b28654804ab72881d577d87c3d5c65e2bc |
| Headers | show |
diff --git a/arch/arm/crypto/aes-ce-glue.c b/arch/arm/crypto/aes-ce-glue.c index da3c0428507b..aef022a87c53 100644 --- a/arch/arm/crypto/aes-ce-glue.c +++ b/arch/arm/crypto/aes-ce-glue.c @@ -284,7 +284,7 @@ static int ctr_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst, err = blkcipher_walk_done(desc, &walk, walk.nbytes % AES_BLOCK_SIZE); } - if (nbytes) { + if (walk.nbytes % AES_BLOCK_SIZE) { u8 *tdst = walk.dst.virt.addr + blocks * AES_BLOCK_SIZE; u8 *tsrc = walk.src.virt.addr + blocks * AES_BLOCK_SIZE; u8 __aligned(8) tail[AES_BLOCK_SIZE];
The AES-CTR glue code avoids calling into the blkcipher API for the tail portion of the walk, by comparing the remainder of walk.nbytes modulo AES_BLOCK_SIZE with the residual nbytes, and jumping straight into the tail processing block if they are equal. This tail processing block checks whether nbytes != 0, and does nothing otherwise. However, in case of an allocation failure in the blkcipher layer, we may enter this code with walk.nbytes == 0, while nbytes > 0. In this case, we should not dereference the source and destination pointers, since they may be NULL. So instead of checking for nbytes != 0, check for (walk.nbytes % AES_BLOCK_SIZE) != 0, which implies the former in non-error conditions. Fixes: 86464859cc77 ("crypto: arm - AES in ECB/CBC/CTR/XTS modes using ARMv8 Crypto Extensions") Reported-by: xiakaixu <xiakaixu@huawei.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- arch/arm/crypto/aes-ce-glue.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html