On Sat, Jul 19, 2014 at 10:26:57AM -0400, Benjamin Romer wrote:
> +ssize_t store_chipsetready(struct device *dev, struct device_attribute *attr,
> + const char *buf, size_t count)
> {
> - char buf[512];
> - char *token, *p;
> -
> - if (count > sizeof(buf) - 1) {
> - LOGERR("chipset_proc_write: count (%d) exceeds size of buffer (%d)",
> - (int) count, (int) sizeof(buffer));
> - return -EINVAL;
> - }
> - if (copy_from_user(buf, buffer, count)) {
> - LOGERR("chipset_proc_write: copy_from_user failed");
> - return -EFAULT;
> - }
> - buf[count] = '\0';
> -
> - p = buf;
> - token = gettoken(&p);
> -
> - if (strcmp(token, "CALLHOMEDISK_MOUNTED") == 0) {
> - token = gettoken(&p);
> - /* The Call Home Disk has been mounted */
> - if (strcmp(token, "0") == 0)
> - chipset_events[0] = 1;
> - } else if (strcmp(token, "MODULES_LOADED") == 0) {
> - token = gettoken(&p);
> - /* All modules for the partition have been loaded */
> - if (strcmp(token, "0") == 0)
> - chipset_events[1] = 1;
> - } else if (token == NULL) {
> - /* No event specified */
> - LOGERR("No event was specified to send CHIPSET_READY response");
> - return -1;
> + char msgtype[64];
> + int msgparam;
> +
> + if (sscanf(buf, "%63s %d", msgtype, &msgparam) == 2) {
> + if (strcmp(msgtype, "CALLHOMEDISK_MOUNTED") == 0) {
> + /* The Call Home Disk has been mounted */
> + if (msgparam == 0)
> + chipset_events[0] = 1;
> + } else if (strcmp(msgtype, "MODULES_LOADED") == 0) {
> + /* All modules for the partition have been loaded */
> + if (msgparam == 0)
> + chipset_events[1] = 1;
> + } else {
> + /* Unsupported event specified */
> + LOGERR("%s is an invalid event for sending CHIPSET_READY response",
> + msgtype);
> + return -1;
> + }
> } else {
> - /* Unsupported event specified */
> - LOGERR("%s is an invalid event for sending CHIPSET_READY response", token);
> + LOGERR("malformed input to chipsetready attribute");
> return -1;
How nice, a simple way to create a DoS in the kernel log by just writing
odd data to a sysfs file :(
Also, don't make up error numbers that you are returning to userspace,
-1 is not a valid one for what you mean here. Or I really don't know
what you mean...
thanks,
greg k-h
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