diff mbox series

i2c: Add a length check to the SMBus write handling

Message ID 20181203125250.11195-1-minyard@acm.org (mailing list archive)
State New, archived
Headers show
Series i2c: Add a length check to the SMBus write handling | expand

Commit Message

Corey Minyard Dec. 3, 2018, 12:52 p.m. UTC 
From: Corey Minyard <cminyard@mvista.com>

Avoid an overflow.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Cc: QEMU Stable <qemu-stable@nongnu.org>
---
 hw/i2c/smbus.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

Comments

Peter Maydell Dec. 3, 2018, 1:45 p.m. UTC | #1 
On Mon, 3 Dec 2018 at 12:53, <minyard@acm.org> wrote:
>
> From: Corey Minyard <cminyard@mvista.com>
>
> Avoid an overflow.
>
> Signed-off-by: Corey Minyard <cminyard@mvista.com>
> Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> Cc: QEMU Stable <qemu-stable@nongnu.org>

Applied to master for rc4, thanks.

-- PMM
diff mbox series

Patch

diff --git a/hw/i2c/smbus.c b/hw/i2c/smbus.c
index 6ff77c582f..30028bfcc2 100644
--- a/hw/i2c/smbus.c
+++ b/hw/i2c/smbus.c
@@ -193,7 +193,11 @@  static int smbus_i2c_send(I2CSlave *s, uint8_t data)
     switch (dev->mode) {
     case SMBUS_WRITE_DATA:
         DPRINTF("Write data %02x\n", data);
-        dev->data_buf[dev->data_len++] = data;
+        if (dev->data_len >= sizeof(dev->data_buf)) {
+            BADF("Too many bytes sent\n");
+        } else {
+            dev->data_buf[dev->data_len++] = data;
+        }
         break;
     default:
         BADF("Unexpected write in state %d\n", dev->mode);