1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/serial/mfd.c b/drivers/serial/mfd.c
index 5dff45c76d3..ad35130cd8a 100644
--- a/drivers/serial/mfd.c
+++ b/drivers/serial/mfd.c
@@ -172,6 +172,9 @@ static ssize_t port_show_regs(struct file *file, char __user *user_buf,
         len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
                         "DIV: \t\t0x%08x\n", serial_in(up, UART_DIV));
 
+        if (len > HSU_REGS_BUFSIZE)
+                len = HSU_REGS_BUFSIZE;
+
         ret =  simple_read_from_buffer(user_buf, count, ppos, buf, len);
         kfree(buf);
         return ret;
@@ -219,6 +222,9 @@ static ssize_t dma_show_regs(struct file *file, char __user *user_buf,
         len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
                         "D0TSR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_D3TSR));
 
+        if (len > HSU_REGS_BUFSIZE)
+                len = HSU_REGS_BUFSIZE;
+
         ret =  simple_read_from_buffer(user_buf, count, ppos, buf, len);
         kfree(buf);
         return ret;