From: H Hartley Sweeten Date: Fri, 20 Feb 2015 19:52:27 +0000 (-0700) Subject: staging: comedi: cb_pcidas64: fix possible integer overflow X-Git-Tag: v4.1-rc1~152^2~138^2~753 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=1f5fc964866dabec6db6e7eaf8865838b1436a8e;p=karo-tx-linux.git staging: comedi: cb_pcidas64: fix possible integer overflow The {min,max}_scan_divisor values could overflow due to the unsigned int * insigned int calculation. Change the type of the local variable 'convert_divisor' to unsigned long long to avoid the possible overflow. Reported-by: coverity (CID 200653) Signed-off-by: H Hartley Sweeten Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/staging/comedi/drivers/cb_pcidas64.c b/drivers/staging/comedi/drivers/cb_pcidas64.c index 5b43e4e6d037..9836c877c910 100644 --- a/drivers/staging/comedi/drivers/cb_pcidas64.c +++ b/drivers/staging/comedi/drivers/cb_pcidas64.c @@ -2001,7 +2001,8 @@ static unsigned int get_divisor(unsigned int ns, unsigned int flags) static void check_adc_timing(struct comedi_device *dev, struct comedi_cmd *cmd) { const struct pcidas64_board *thisboard = dev->board_ptr; - unsigned int convert_divisor = 0, scan_divisor; + unsigned long long convert_divisor = 0; + unsigned int scan_divisor; static const int min_convert_divisor = 3; static const int max_convert_divisor = max_counter_value + min_convert_divisor; @@ -2027,7 +2028,6 @@ static void check_adc_timing(struct comedi_device *dev, struct comedi_cmd *cmd) if (cmd->scan_begin_src == TRIG_TIMER) { scan_divisor = get_divisor(cmd->scan_begin_arg, cmd->flags); if (cmd->convert_src == TRIG_TIMER) { - /* XXX check for integer overflows */ min_scan_divisor = convert_divisor * cmd->chanlist_len; max_scan_divisor = (convert_divisor * cmd->chanlist_len - 1) +