pam_filter: fix potential off-by-one heap buffer overflow

Reported by gcc-10 -Wstringop-overflow:

In file included from /usr/include/string.h:494,
                 from modules/pam_filter/pam_filter.c:14:
In function 'strcpy',
    inlined from 'process_args' at modules/pam_filter/pam_filter.c:137:2,
    inlined from 'need_a_filter.isra' at modules/pam_filter/pam_filter.c:618:12:
/usr/include/x86_64-linux-gnu/bits/string_fortified.h:90:10: warning: '__builtin_memcpy' writing 6 bytes into a region of size 5 [-Wstringop-overflow=]
   90 |   return __builtin___strcpy_chk (__dest, __src, __bos (__dest));
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
modules/pam_filter/pam_filter.c: In function 'need_a_filter.isra':
modules/pam_filter/pam_filter.c:128:21: note: at offset 0 to an object with size 5 allocated by 'malloc' here
  128 |  levp[0] = (char *) malloc(size);
      |                     ^~~~~~~~~~~~

* modules/pam_filter/pam_filter.c (process_args): Fix off-by-one heap
buffer overflow in case of a filter without arguments (argc == 0).

0 files changed, 0 insertions, 0 deletions