diff --git a/cfg/posix.cfg b/cfg/posix.cfg
index fd393d405..a4eedcefe 100644
--- a/cfg/posix.cfg
+++ b/cfg/posix.cfg
@@ -4646,6 +4646,23 @@ The function 'mktemp' is considered to be dangerous due to race conditions and s
     <leak-ignore/>
     <warn severity="portability">Non reentrant function 'getlogin' called. For threadsafe applications it is recommended to use the reentrant replacement function 'getlogin_r'.</warn>
   </function>
+  <!-- https://man7.org/linux/man-pages/man3/getlogin.3.html -->
+  <!-- int getlogin_r(char *buf, size_t bufsize); -->
+  <function name="getlogin_r">
+    <returnValue type="int"/>
+    <use-retval/>
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <arg nr="1" direction="out">
+      <not-null/>
+      <minsize type="argvalue" arg="2"/>
+    </arg>
+    <arg nr="2" direction="in">
+      <not-bool/>
+      <not-uninit/>
+      <valid>0:</valid>
+    </arg>
+  </function>
   <!-- char *ctermid(char *s); -->
   <function name="ctermid">
     <returnValue type="char *"/>
diff --git a/test/cfg/posix.c b/test/cfg/posix.c
index 36daa93e4..80153087c 100644
--- a/test/cfg/posix.c
+++ b/test/cfg/posix.c
@@ -31,6 +31,13 @@
 #include <wchar.h>
 #include <string.h>
 
+int nullPointer_getlogin_r(char *buf, size_t bufsize)
+{
+    // cppcheck-suppress nullPointer
+    (void)getlogin_r(NULL,bufsize);
+    return getlogin_r(buf,bufsize);
+}
+
 ssize_t uninitvar_pread(int fd, void *buf, size_t nbyte, off_t offset)
 {
     int Fd;