The local variable 'bi' comes from userspace. If userspace passed a
large number to 'bi.data.calibrate', there would be an integer overflow
in the following line:
        s->hdlctx.calibrate = bi.data.calibrate * s->par.bitrate / 16;

Signed-off-by: Wenliang Fan <fanwle...@gmail.com>
---
 drivers/net/hamradio/hdlcdrv.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/hamradio/hdlcdrv.c b/drivers/net/hamradio/hdlcdrv.c
index 3169252..5d78c1d 100644
--- a/drivers/net/hamradio/hdlcdrv.c
+++ b/drivers/net/hamradio/hdlcdrv.c
@@ -571,6 +571,8 @@ static int hdlcdrv_ioctl(struct net_device *dev, struct 
ifreq *ifr, int cmd)
        case HDLCDRVCTL_CALIBRATE:
                if(!capable(CAP_SYS_RAWIO))
                        return -EPERM;
+               if (bi.data.calibrate > INT_MAX / s->par.bitrate)
+                       return -EINVAL;
                s->hdlctx.calibrate = bi.data.calibrate * s->par.bitrate / 16;
                return 0;
 
-- 
1.8.5.rc1.28.g7061504

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