Bug#32167 another privilege bypass with DATA/INDEX DIRECTORY.

            
            test_if_data_home_dir fixed to look into real path.
            Checks added to mi_open for symlinks into data home directory.

per-file messages:
        include/my_sys.h
          Bug#32167 another privilege bypass with DATA/INDEX DIRECTORY.
          
          my_is_symlink interface added
        include/myisam.h
          Bug#32167 another privilege bypass with DATA/INDEX DIRECTORY.
          
          myisam_test_invalid_symlink interface added
        myisam/mi_check.c
          Bug#32167 another privilege bypass with DATA/INDEX DIRECTORY.
          
          mi_open_datafile calls modified
        myisam/mi_open.c
          Bug#32167 another privilege bypass with DATA/INDEX DIRECTORY.
          
          code added to mi_open to check for symlinks into data home directory.
          mi_open_datafile now accepts 'original' file path to check if it's
          an allowed symlink.
        myisam/mi_static.c
          Bug#32167 another privilege bypass with DATA/INDEX DIRECTORY.
          
          myisam_test_invlaid_symlink defined
        myisam/myisamchk.c
          Bug#32167 another privilege bypass with DATA/INDEX DIRECTORY.
          
          mi_open_datafile call modified
        myisam/myisamdef.h
          Bug#32167 another privilege bypass with DATA/INDEX DIRECTORY.
          
          mi_open_datafile interface modified - 'real_path' parameter added
        mysql-test/r/symlink.test
          Bug#32167 another privilege bypass with DATA/INDEX DIRECTORY.
          
          error codes corrected as some patch now rejected pointing inside datahome
        mysql-test/r/symlink.result
          Bug#32167 another privilege bypass with DATA/INDEX DIRECTORY.
          
          error messages corrected in the result
        mysys/my_symlink.c
          Bug#32167 another privilege bypass with DATA/INDEX DIRECTORY.
          
          my_is_symlink() implementsd
          my_realpath() now returns the 'realpath' even if a file isn't a symlink
        sql/mysql_priv.h
          Bug#32167 another privilege bypass with DATA/INDEX DIRECTORY.
          
          test_if_data_home_dir interface
        sql/mysqld.cc
          Bug#32167 another privilege bypass with DATA/INDEX DIRECTORY.
          
          myisam_test_invalid_symlik set with the 'test_if_data_home_dir'
        sql/sql_parse.cc
          Bug#32167 another privilege bypass with DATA/INDEX DIRECTORY.
          
          error messages corrected
          test_if_data_home_dir code fixed

1 files changed, 24 insertions, 23 deletions

diff --git a/mysys/my_symlink.c b/mysys/my_symlink.c
index 810c0c72632..c07be41066f 100644
--- a/mysys/my_symlink.c
+++ b/mysys/my_symlink.c
@@ -106,38 +106,39 @@ int my_symlink(const char *content, const char *linkname, myf MyFlags)
 #define BUFF_LEN FN_LEN
 #endif
 
+
+int my_is_symlink(const char *filename __attribute__((unused)))
+{
+  struct stat stat_buff;
+  return !lstat(filename, &stat_buff) && S_ISLNK(stat_buff.st_mode);
+}
+
+
 int my_realpath(char *to, const char *filename,
 		myf MyFlags __attribute__((unused)))
 {
 #if defined(HAVE_REALPATH) && !defined(HAVE_purify) && !defined(HAVE_BROKEN_REALPATH)
   int result=0;
   char buff[BUFF_LEN];
-  struct stat stat_buff;
+  char *ptr;
   DBUG_ENTER("my_realpath");
 
-  if (!(MyFlags & MY_RESOLVE_LINK) ||
-      (!lstat(filename,&stat_buff) && S_ISLNK(stat_buff.st_mode)))
-  {
-    char *ptr;
-    DBUG_PRINT("info",("executing realpath"));
-    if ((ptr=realpath(filename,buff)))
-    {
+  DBUG_PRINT("info",("executing realpath"));
+  if ((ptr=realpath(filename,buff)))
       strmake(to,ptr,FN_REFLEN-1);
-    }
-    else
-    {
-      /*
-	Realpath didn't work;  Use my_load_path() which is a poor substitute
-	original name but will at least be able to resolve paths that starts
-	with '.'.
-      */
-      DBUG_PRINT("error",("realpath failed with errno: %d", errno));
-      my_errno=errno;
-      if (MyFlags & MY_WME)
-	my_error(EE_REALPATH, MYF(0), filename, my_errno);
-      my_load_path(to, filename, NullS);
-      result= -1;
-    }
+  else
+  {
+    /*
+      Realpath didn't work;  Use my_load_path() which is a poor substitute
+      original name but will at least be able to resolve paths that starts
+      with '.'.
+    */
+    DBUG_PRINT("error",("realpath failed with errno: %d", errno));
+    my_errno=errno;
+    if (MyFlags & MY_WME)
+      my_error(EE_REALPATH, MYF(0), filename, my_errno);
+    my_load_path(to, filename, NullS);
+    result= -1;
   }
   DBUG_RETURN(result);
 #else