fix misuse of getpwuid_r in cuserid

getpwuid_r can return 0 but without a result in the case where there
was no error but no record exists. in that case cuserid was treating
it as success and copying junk out of pw.pw_name to the output buffer.

diff --git a/src/legacy/cuserid.c b/src/legacy/cuserid.c
index 3ff115a..07866ac 100644 (file)
--- a/src/legacy/cuserid.c
+++ b/src/legacy/cuserid.c
@@ -9,7 +9,8 @@ char *cuserid(char *buf)
        static char usridbuf[L_cuserid];
        struct passwd pw, *ppw;
        long pwb[256];
-       if (getpwuid_r(geteuid(), &pw, (void *)pwb, sizeof pwb, &ppw))
+       getpwuid_r(geteuid(), &pw, (void *)pwb, sizeof pwb, &ppw);
+       if (!ppw)
                return 0;
        size_t len = strnlen(pw.pw_name, L_cuserid);
        if (len == L_cuserid)