| Message ID | 20220120213131.GA32119@embeddedor (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [next] USB: serial: ti_usb_3410_5052: Use struct_size() helper in ti_write_byte() | expand |
On Thu, Jan 20, 2022 at 03:31:31PM -0600, Gustavo A. R. Silva wrote: > Make use of the struct_size() helper instead of an open-coded version, > in order to avoid any potential type mistakes or integer overflows that, > in the worst scenario, could lead to heap overflows. > > Also, address the following sparse warnings: > drivers/usb/serial/ti_usb_3410_5052.c:1521:16: warning: using sizeof on a flexible structure > > Link: https://github.com/KSPP/linux/issues/174 > Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Looks good. Reviewed-by: Kees Cook <keescook@chromium.org>
On Thu, Jan 20, 2022 at 03:31:31PM -0600, Gustavo A. R. Silva wrote: > Make use of the struct_size() helper instead of an open-coded version, > in order to avoid any potential type mistakes or integer overflows that, > in the worst scenario, could lead to heap overflows. This boiler-plate motivation doesn't apply here since the "variable" size is in fact constant. > Also, address the following sparse warnings: > drivers/usb/serial/ti_usb_3410_5052.c:1521:16: warning: using sizeof on a flexible structure And this bit is again bogus, since this off-by-default warning would still be there with this patch applied. > Link: https://github.com/KSPP/linux/issues/174 > Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> > --- > drivers/usb/serial/ti_usb_3410_5052.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/usb/serial/ti_usb_3410_5052.c b/drivers/usb/serial/ti_usb_3410_5052.c > index 18c0bd853392..03f98e61626f 100644 > --- a/drivers/usb/serial/ti_usb_3410_5052.c > +++ b/drivers/usb/serial/ti_usb_3410_5052.c > @@ -1512,13 +1512,13 @@ static int ti_write_byte(struct usb_serial_port *port, > u8 mask, u8 byte) > { > int status; > - unsigned int size; > + size_t size; > struct ti_write_data_bytes *data; > > dev_dbg(&port->dev, "%s - addr 0x%08lX, mask 0x%02X, byte 0x%02X\n", __func__, > addr, mask, byte); > > - size = sizeof(struct ti_write_data_bytes) + 2; > + size = struct_size(data, bData, 2); I guess the change itself is fine otherwise and could be motivated as documenting the constant. At least as long as the compiler is smart enough to not generate any additional code for this, there wouldn't be any downsides. > data = kmalloc(size, GFP_KERNEL); > if (!data) > return -ENOMEM; Johan
diff --git a/drivers/usb/serial/ti_usb_3410_5052.c b/drivers/usb/serial/ti_usb_3410_5052.c index 18c0bd853392..03f98e61626f 100644 --- a/drivers/usb/serial/ti_usb_3410_5052.c +++ b/drivers/usb/serial/ti_usb_3410_5052.c @@ -1512,13 +1512,13 @@ static int ti_write_byte(struct usb_serial_port *port, u8 mask, u8 byte) { int status; - unsigned int size; + size_t size; struct ti_write_data_bytes *data; dev_dbg(&port->dev, "%s - addr 0x%08lX, mask 0x%02X, byte 0x%02X\n", __func__, addr, mask, byte); - size = sizeof(struct ti_write_data_bytes) + 2; + size = struct_size(data, bData, 2); data = kmalloc(size, GFP_KERNEL); if (!data) return -ENOMEM;
Make use of the struct_size() helper instead of an open-coded version, in order to avoid any potential type mistakes or integer overflows that, in the worst scenario, could lead to heap overflows. Also, address the following sparse warnings: drivers/usb/serial/ti_usb_3410_5052.c:1521:16: warning: using sizeof on a flexible structure Link: https://github.com/KSPP/linux/issues/174 Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> --- drivers/usb/serial/ti_usb_3410_5052.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)