user: fix a possible integer overflow This was flagged by a run of Fortify, though I think it's pretty dubious given the sysconf() contract, which returns either -1 or a positive number.
Change-Id: I08b4e47862b0f05558c4420c9b5d6ddd53ccd156 Reviewed-on: http://gerrit.cloudera.org:8080/9975 Reviewed-by: Dan Burkert <danburk...@apache.org> Tested-by: Kudu Jenkins Project: http://git-wip-us.apache.org/repos/asf/kudu/repo Commit: http://git-wip-us.apache.org/repos/asf/kudu/commit/05bec2c1 Tree: http://git-wip-us.apache.org/repos/asf/kudu/tree/05bec2c1 Diff: http://git-wip-us.apache.org/repos/asf/kudu/diff/05bec2c1 Branch: refs/heads/master Commit: 05bec2c1c0740ad6319d65cb5e4d5507e9b6c818 Parents: d18be56 Author: Adar Dembo <a...@cloudera.com> Authored: Tue Apr 10 11:03:52 2018 -0700 Committer: Adar Dembo <a...@cloudera.com> Committed: Tue Apr 10 20:52:46 2018 +0000 ---------------------------------------------------------------------- src/kudu/util/user.cc | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/kudu/blob/05bec2c1/src/kudu/util/user.cc ---------------------------------------------------------------------- diff --git a/src/kudu/util/user.cc b/src/kudu/util/user.cc index 2d12267..f44e040 100644 --- a/src/kudu/util/user.cc +++ b/src/kudu/util/user.cc @@ -21,6 +21,7 @@ #include <unistd.h> #include <cerrno> +#include <cstdint> #include <cstdlib> #include <mutex> #include <string> @@ -44,10 +45,10 @@ Status DoGetLoggedInUser(string* user_name) { struct passwd pwd; struct passwd *result; - size_t bufsize = sysconf(_SC_GETPW_R_SIZE_MAX); - if (bufsize == -1) { // Value was indeterminate. - bufsize = 16384; // Should be more than enough, per the man page. - } + // Get the system-defined limit for usernames. If the value was indeterminate, + // use a constant that should be more than enough, per the man page. + int64_t retval = sysconf(_SC_GETPW_R_SIZE_MAX); + size_t bufsize = retval > 0 ? retval : 16384; gscoped_ptr<char[], FreeDeleter> buf(static_cast<char *>(malloc(bufsize))); if (buf.get() == nullptr) {
