> On Jun 29, 2017, at 7:24 PM, Ben Hutchings <ben.hutchings@xxxxxxxxxxxxxxx> wrote: > > On Tue, 2017-06-27 at 14:49 +0200, Greg Kroah-Hartman wrote: >> 4.4-stable review patch. If anyone has any objections, please let me know. >> >> ------------------ >> >> From: Ilya Matveychikov <matvejchikov@xxxxxxxxx> >> >> commit a91e0f680bcd9e10c253ae8b62462a38bd48f09f upstream. >> >> When using get_options() it's possible to specify a range of numbers, >> like 1-100500. The problem is that it doesn't track array size while >> calling internally to get_range() which iterates over the range and >> fills the memory with numbers. > [...] >> --- a/lib/cmdline.c >> +++ b/lib/cmdline.c >> @@ -22,14 +22,14 @@ >> * the values[M, M+1, ..., N] into the ints array in get_options. >> */ >> >> -static int get_range(char **str, int *pint) >> +static int get_range(char **str, int *pint, int n) >> { >> int x, inc_counter, upper_range; >> >> (*str)++; >> upper_range = simple_strtol((*str), NULL, 0); >> inc_counter = upper_range - *pint; >> - for (x = *pint; x < upper_range; x++) >> + for (x = *pint; n && x < upper_range; x++, n--) >> *pint++ = x; >> return inc_counter; >> } > > But this still returns the number of integers in the range (minus 1)... > >> @@ -96,7 +96,7 @@ char *get_options(const char *str, int n >> break; >> if (res == 3) { >> int range_nums; >> - range_nums = get_range((char **)&str, ints + i); >> + range_nums = get_range((char **)&str, ints + i, nints - i); >> if (range_nums < 0) >> break; >> /* > > ...so that get_options() may set i > nints and ints[0] > nints - 1. > That will presumably result in out-of-bounds reads in callers. > > (This set of functions really deserves to be given a test suite and then > rewritten, because they are a *mess*.) > Please review the approach of fixing that: https://lkml.org/lkml/2017/9/19/105 > Ben. > > -- > Ben Hutchings > Software Developer, Codethink Ltd. > >