fpga: prevent integer overflow in dfl_feature_ioctl_set_irq()

[ Upstream commit 939bc5453b8cbdde9f1e5110ce8309aedb1b501a ]

The "hdr.count * sizeof(s32)" multiplication can overflow on 32 bit
systems leading to memory corruption.  Use array_size() to fix that.

Fixes: 322b598be4d9 ("fpga: dfl: introduce interrupt trigger setting API")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Xu Yilun <yilun.xu@intel.com>
Link: https://lore.kernel.org/r/YxBAtYCM38dM7yzI@kili
Signed-off-by: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c
index f86666cf2c6a867f53a10bc407074a6be1c3d3f6..c38143ef23c6423be2c4cae15ce172b5d3035d44 100644 (file)
--- a/drivers/fpga/dfl.c
+++ b/drivers/fpga/dfl.c
@@ -1864,7 +1864,7 @@ long dfl_feature_ioctl_set_irq(struct platform_device *pdev,
                return -EINVAL;
 
        fds = memdup_user((void __user *)(arg + sizeof(hdr)),
-                         hdr.count * sizeof(s32));
+                         array_size(hdr.count, sizeof(s32)));
        if (IS_ERR(fds))
                return PTR_ERR(fds);