"len" hasn't been properly range checked so we shouldn't use it as an array offset. This can only be written to by root but it would still be annoying to accidentally write more than 3 characters and corrupt your memory. Signed-off-by: Dan Carpenter <error27@xxxxxxxxx> --- v2. Removed a superfluous chunk from my first patch. I didn't understand how ->maxlen worked. diff --git a/drivers/s390/char/sclp_async.c b/drivers/s390/char/sclp_async.c index f449c69..38a9f55 100644 --- a/drivers/s390/char/sclp_async.c +++ b/drivers/s390/char/sclp_async.c @@ -84,7 +84,7 @@ static int proc_handler_callhome(struct ctl_table *ctl, int write, rc = copy_from_user(buf, buffer, sizeof(buf)); if (rc != 0) return -EFAULT; - buf[len - 1] = '\0'; + buf[sizeof(buf) - 1] = '\0'; if (strict_strtoul(buf, 0, &val) != 0) return -EINVAL; if (val != 0 && val != 1) -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
