userns: add argument sanity checking

In find_new_sub_{u,g}ids, check for min, count and max values.

In idmapping.c:get_map_ranges(), make sure that the value passed
in for ranges did not overflow.  Couldn't happen with the current
code, but this is a sanity check for any future potential mis-uses.

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
userns.2
Serge Hallyn 10 years ago
parent ca0f352884
commit df3c8c1f7f
  1. 8
      libmisc/find_new_sub_gids.c
  2. 8
      libmisc/find_new_sub_uids.c
  3. 10
      libmisc/idmapping.c

@ -58,6 +58,14 @@ int find_new_sub_gids (const char *owner,
max = getdef_ulong ("SUB_GID_MAX", 600100000UL);
count = getdef_ulong ("SUB_GID_COUNT", 10000);
if (min >= max || count >= max || (min + count) >= max) {
(void) fprintf (stderr,
_("%s: Invalid configuration: SUB_GID_MIN (%lu),"
" SUB_GID_MAX (%lu), SUB_GID_COUNT (%lu)\n"),
Prog, min, max, count);
return -1;
}
/* Is there a preferred range that works? */
if ((*range_count != 0) &&
(*range_start >= min) &&

@ -58,6 +58,14 @@ int find_new_sub_uids (const char *owner,
max = getdef_ulong ("SUB_UID_MAX", 600100000UL);
count = getdef_ulong ("SUB_UID_COUNT", 10000);
if (min >= max || count >= max || (min + count) >= max) {
(void) fprintf (stderr,
_("%s: Invalid configuration: SUB_UID_MIN (%lu),"
" SUB_UID_MAX (%lu), SUB_UID_COUNT (%lu)\n"),
Prog, min, max, count);
return -1;
}
/* Is there a preferred range that works? */
if ((*range_count != 0) &&
(*range_start >= min) &&

@ -41,6 +41,16 @@ struct map_range *get_map_ranges(int ranges, int argc, char **argv)
struct map_range *mappings, *mapping;
int idx, argidx;
if (ranges < 0 || argc < 0) {
fprintf(stderr, "%s: error calculating number of arguments\n", Prog);
return NULL;
}
if (ranges != ((argc - 2) + 2) / 3) {
fprintf(stderr, "%s: ranges: %u is wrong for argc: %d\n", Prog, ranges, argc);
return NULL;
}
if ((ranges * 3) > argc) {
fprintf(stderr, "ranges: %u argc: %d\n",
ranges, argc);

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