misc: xilinx_sdfec: Fix a couple small information leaks

These structs have holes in them so we end up disclosing a few bytes of
uninitialized stack data.

drivers/misc/xilinx_sdfec.c:305 xsdfec_get_status() warn: check that 'status' doesn't leak information (struct has a hole after 'activity')
drivers/misc/xilinx_sdfec.c:449 xsdfec_get_turbo() warn: check that 'turbo_params' doesn't leak information (struct has a hole after 'scale')

We need to zero out the holes with memset().

Fixes: 6bd6a690c2e7 ("misc: xilinx_sdfec: Add stats & status ioctls")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Dragan Cvetic <dragan.cvetic@xilinx.com>
Reviewed-by: Michal Simek <michal.simek@xilinx.com>
Link: https://lore.kernel.org/r/20190821070606.GA26957@mwanda
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/misc/xilinx_sdfec.c b/drivers/misc/xilinx_sdfec.c
index 912e939..dc1b8b4 100644 (file)
--- a/drivers/misc/xilinx_sdfec.c
+++ b/drivers/misc/xilinx_sdfec.c
@@ -295,6 +295,7 @@ static int xsdfec_get_status(struct xsdfec_dev *xsdfec, void __user *arg)
        struct xsdfec_status status;
        int err;
 
+       memset(&status, 0, sizeof(status));
        spin_lock_irqsave(&xsdfec->error_data_lock, xsdfec->flags);
        status.state = xsdfec->state;
        xsdfec->state_updated = false;
@@ -440,6 +441,7 @@ static int xsdfec_get_turbo(struct xsdfec_dev *xsdfec, void __user *arg)
        if (xsdfec->config.code == XSDFEC_LDPC_CODE)
                return -EIO;
 
+       memset(&turbo_params, 0, sizeof(turbo_params));
        reg_value = xsdfec_regread(xsdfec, XSDFEC_TURBO_ADDR);
 
        turbo_params.scale = (reg_value & XSDFEC_TURBO_SCALE_MASK) >>