pam_issue: fix potential read out of bounds

Reported by gcc-10 -Warray-bounds:

In file included from /usr/include/string.h:494,
                 from modules/pam_issue/pam_issue.c:19:
In function 'strncat',
    inlined from 'read_issue_quoted' at modules/pam_issue/pam_issue.c:197:3:
/usr/include/x86_64-linux-gnu/bits/string_fortified.h:136:10: error: '__builtin___strncat_chk' offset [260, 389] from the object at 'uts' is out of the bounds of referenced subobject 'version' with type 'char[65]' at offset 195 [-Werror=array-bounds]
  136 |   return __builtin___strncat_chk (__dest, __src, __len, __bos (__dest));
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from modules/pam_issue/pam_issue.c:26:
modules/pam_issue/pam_issue.c: In function 'read_issue_quoted':
/usr/include/x86_64-linux-gnu/sys/utsname.h:59:10: note: subobject 'version' declared here
   59 |     char version[_UTSNAME_VERSION_LENGTH];
      |          ^~~~~~~
In file included from /usr/include/string.h:494,
                 from modules/pam_issue/pam_issue.c:19:
In function 'strncat',
    inlined from 'read_issue_quoted' at modules/pam_issue/pam_issue.c:188:3:
/usr/include/x86_64-linux-gnu/bits/string_fortified.h:136:10: error: '__builtin___strncat_chk' offset [65, 389] from the object at 'uts' is out of the bounds of referenced subobject 'sysname' with type 'char[65]' at offset 0 [-Werror=array-bounds]
  136 |   return __builtin___strncat_chk (__dest, __src, __len, __bos (__dest));
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from modules/pam_issue/pam_issue.c:26:
modules/pam_issue/pam_issue.c: In function 'read_issue_quoted':
/usr/include/x86_64-linux-gnu/sys/utsname.h:51:10: note: subobject 'sysname' declared here
   51 |     char sysname[_UTSNAME_SYSNAME_LENGTH];
      |          ^~~~~~~
In file included from /usr/include/string.h:494,
                 from modules/pam_issue/pam_issue.c:19:
In function 'strncat',
    inlined from 'read_issue_quoted' at modules/pam_issue/pam_issue.c:194:3:
/usr/include/x86_64-linux-gnu/bits/string_fortified.h:136:10: error: '__builtin___strncat_chk' offset [195, 389] from the object at 'uts' is out of the bounds of referenced subobject 'release' with type 'char[65]' at offset 130 [-Werror=array-bounds]
  136 |   return __builtin___strncat_chk (__dest, __src, __len, __bos (__dest));
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from modules/pam_issue/pam_issue.c:26:
modules/pam_issue/pam_issue.c: In function 'read_issue_quoted':
/usr/include/x86_64-linux-gnu/sys/utsname.h:57:10: note: subobject 'release' declared here
   57 |     char release[_UTSNAME_RELEASE_LENGTH];
      |          ^~~~~~~
In file included from /usr/include/string.h:494,
                 from modules/pam_issue/pam_issue.c:19:
In function 'strncat',
    inlined from 'read_issue_quoted' at modules/pam_issue/pam_issue.c:191:3:
/usr/include/x86_64-linux-gnu/bits/string_fortified.h:136:10: error: '__builtin___strncat_chk' offset [130, 389] from the object at 'uts' is out of the bounds of referenced subobject 'nodename' with type 'char[65]' at offset 65 [-Werror=array-bounds]
  136 |   return __builtin___strncat_chk (__dest, __src, __len, __bos (__dest));
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from modules/pam_issue/pam_issue.c:26:
modules/pam_issue/pam_issue.c: In function 'read_issue_quoted':
/usr/include/x86_64-linux-gnu/sys/utsname.h:54:10: note: subobject 'nodename' declared here
   54 |     char nodename[_UTSNAME_NODENAME_LENGTH];
      |          ^~~~~~~~
In file included from /usr/include/string.h:494,
                 from modules/pam_issue/pam_issue.c:19:
In function 'strncat',
    inlined from 'read_issue_quoted' at modules/pam_issue/pam_issue.c:200:3:
/usr/include/x86_64-linux-gnu/bits/string_fortified.h:136:10: error: '__builtin___strncat_chk' offset [325, 389] from the object at 'uts' is out of the bounds of referenced subobject 'machine' with type 'char[65]' at offset 260 [-Werror=array-bounds]
  136 |   return __builtin___strncat_chk (__dest, __src, __len, __bos (__dest));
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from modules/pam_issue/pam_issue.c:26:
modules/pam_issue/pam_issue.c: In function 'read_issue_quoted':
/usr/include/x86_64-linux-gnu/sys/utsname.h:62:10: note: subobject 'machine' declared here
   62 |     char machine[_UTSNAME_MACHINE_LENGTH];
      |          ^~~~~~~

* modules/pam_issue/pam_issue.c (read_issue_quoted): Rewrite to avoid
strncat from potentially not null-terminated string buffer fields
of struct utsname.

0 files changed, 0 insertions, 0 deletions