In drivers/net/usb/hso.c::hso_create_bulk_serial_device() we have this
code:
...
serial = kzalloc(sizeof(*serial), GFP_KERNEL);
if (!serial)
goto exit;
...
exit:
hso_free_tiomget(serial);
...
hso_free_tiomget() directly dereferences its argument, which in the
example above is a NULL pointer, ouch.
I could just add a 'if (serial)' test at the 'exit' label, but since most
freeing functions in the kernel accept NULL pointers (and it seems like
this was also assumed here) I opted to instead change 'hso_free_tiomget()'
so that it is safe to call it with a NULL argument. I also modified the
function to get rid of a pointles conditional before the call to
'usb_free_urb()' since that function already tests for NULL itself -
besides fixing the NULL deref this change also buys us a few bytes in
size.
Before:
$ size drivers/net/usb/hso.o
text data bss dec hex filename
32200 592 9960 42752 a700 drivers/net/usb/hso.o
After:
$ size drivers/net/usb/hso.o
text data bss dec hex filename
32196 592 9960 42748 a6fc drivers/net/usb/hso.o
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
5b89db0e84