wusbcore: Fix one more crypto-on-the-stack bug

The driver put a constant buffer of all zeros on the stack and
pointed a scatterlist entry at it.  This doesn't work with virtual
stacks.  Use ZERO_PAGE instead.

Cc: stable@vger.kernel.org # 4.9 only
Reported-by: Eric Biggers <ebiggers3@gmail.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/wusbcore/crypto.c b/drivers/usb/wusbcore/crypto.c
index 79451f7ef1b76301cc881379ad28ce12e4b4dc33..062c205f00469faf1f7226e152f61d920d71f27b 100644 (file)
--- a/drivers/usb/wusbcore/crypto.c
+++ b/drivers/usb/wusbcore/crypto.c
@@ -216,7 +216,6 @@ static int wusb_ccm_mac(struct crypto_skcipher *tfm_cbc,
        struct scatterlist sg[4], sg_dst;
        void *dst_buf;
        size_t dst_size;
-       const u8 bzero[16] = { 0 };
        u8 iv[crypto_skcipher_ivsize(tfm_cbc)];
        size_t zero_padding;
 
@@ -261,7 +260,7 @@ static int wusb_ccm_mac(struct crypto_skcipher *tfm_cbc,
        sg_set_buf(&sg[1], &scratch->b1, sizeof(scratch->b1));
        sg_set_buf(&sg[2], b, blen);
        /* 0 if well behaved :) */
-       sg_set_buf(&sg[3], bzero, zero_padding);
+       sg_set_page(&sg[3], ZERO_PAGE(0), zero_padding, 0);
        sg_init_one(&sg_dst, dst_buf, dst_size);
 
        skcipher_request_set_tfm(req, tfm_cbc);