tar/tar-fix-extract-unlink.patch

From 17debecd7300e94f590b8ce167a8c0735cb6d57d Mon Sep 17 00:00:00 2001
From: Sergey Poznyakoff <gray@gnu.org>
Date: Sat, 22 Oct 2022 12:06:45 +0300
Subject: Fix savannah bug #63123

The bug was introduced by commit 79d1ac38c1, which didn't take into
account all the consequences of returning RECOVER_OK on EEXIST, in
particular interactions with the delayed_set_stat logic.

The commit 79d1ac38c1 is reverted (the bug it was intended to fix
was actually fixed by 79a442d7b0).  Instead:

* src/extract.c (maybe_recoverable): Don't call maybe_recoverable
if EEXIST is reported when UNLINK_FIRST_OLD_FILES option is set.
---
 src/extract.c | 108 +++++++++++++++++++++++++++++++---------------------------
 1 file changed, 58 insertions(+), 50 deletions(-)

diff --git a/src/extract.c b/src/extract.c
index 78de47f..37ab295 100644
--- a/src/extract.c
+++ b/src/extract.c
@@ -679,9 +679,10 @@ fixup_delayed_set_stat (char const *src, char const *dst)
 
 /* After a file/link/directory creation has failed due to ENOENT,
    create all required directories.  Return zero if all the required
-   directories were created, nonzero (issuing a diagnostic) otherwise.  */
+   directories were created, nonzero (issuing a diagnostic) otherwise.
+   Set *INTERDIR_MADE if at least one directory was created.  */
 static int
-make_directories (char *file_name)
+make_directories (char *file_name, bool *interdir_made)
 {
   char *cursor0 = file_name + FILE_SYSTEM_PREFIX_LEN (file_name);
   char *cursor;	        	/* points into the file name */
@@ -725,6 +726,7 @@ make_directories (char *file_name)
 			  desired_mode, AT_SYMLINK_NOFOLLOW);
 
 	  print_for_mkdir (file_name, cursor - file_name, desired_mode);
+	  *interdir_made = true;
 	  parent_end = NULL;
 	}
       else
@@ -879,12 +881,9 @@ maybe_recoverable (char *file_name, bool regular, bool *interdir_made)
       FALLTHROUGH;
 
     case ENOENT:
-      /* Attempt creating missing intermediate directories.  */
-      if (make_directories (file_name) == 0)
-	{
-	  *interdir_made = true;
-	  return RECOVER_OK;
-	}
+      /* Attempt creating missing intermediate directories. */
+      if (make_directories (file_name, interdir_made) == 0)
+	return RECOVER_OK;
       break;
 
     default:
@@ -1072,61 +1071,69 @@ extract_dir (char *file_name, int typeflag)
 	  break;
 	}
 
-      if (errno == EEXIST
-	  && (interdir_made
+      if (errno == EEXIST)
+	{
+	  if (interdir_made
 	      || keep_directory_symlink_option
 	      || old_files_option == NO_OVERWRITE_DIR_OLD_FILES
 	      || old_files_option == DEFAULT_OLD_FILES
-	      || old_files_option == OVERWRITE_OLD_FILES))
-	{
-	  struct stat st;
-	  st.st_mode = 0;
-
-	  if (keep_directory_symlink_option
-	      && is_directory_link (file_name, &st))
-	    return 0;
-
-	  if ((st.st_mode != 0 && fstatat_flags == 0)
-	      || deref_stat (file_name, &st) == 0)
+	      || old_files_option == OVERWRITE_OLD_FILES)
 	    {
-	      current_mode = st.st_mode;
-	      current_mode_mask = ALL_MODE_BITS;
+	      struct stat st;
+	      st.st_mode = 0;
+
+	      if (keep_directory_symlink_option
+		  && is_directory_link (file_name, &st))
+		return 0;
 
-	      if (S_ISDIR (current_mode))
+	      if ((st.st_mode != 0 && fstatat_flags == 0)
+		  || deref_stat (file_name, &st) == 0)
 		{
-		  if (interdir_made)
-		    {
-		      repair_delayed_set_stat (file_name, &st);
-		      return 0;
-		    }
-		  else if (old_files_option == NO_OVERWRITE_DIR_OLD_FILES)
+		  current_mode = st.st_mode;
+		  current_mode_mask = ALL_MODE_BITS;
+
+		  if (S_ISDIR (current_mode))
 		    {
-		      /* Temporarily change the directory mode to a safe
-			 value, to be able to create files in it, should
-			 the need be.
-		      */
-		      mode = safe_dir_mode (&st);
-		      status = fd_chmod(-1, file_name, mode,
-					AT_SYMLINK_NOFOLLOW, DIRTYPE);
-		      if (status == 0)
+		      if (interdir_made)
 			{
-			  /* Store the actual directory mode, to be restored
-			     later.
-			  */
-			  current_stat_info.stat = st;
-			  current_mode = mode & ~ current_umask;
-			  current_mode_mask = MODE_RWX;
-			  atflag = AT_SYMLINK_NOFOLLOW;
-			  break;
+			  repair_delayed_set_stat (file_name, &st);
+			  return 0;
 			}
-		      else
+		      else if (old_files_option == NO_OVERWRITE_DIR_OLD_FILES)
 			{
-			  chmod_error_details (file_name, mode);
+			  /* Temporarily change the directory mode to a safe
+			     value, to be able to create files in it, should
+			     the need be.
+			  */
+			  mode = safe_dir_mode (&st);
+			  status = fd_chmod (-1, file_name, mode,
+					     AT_SYMLINK_NOFOLLOW, DIRTYPE);
+			  if (status == 0)
+			    {
+			      /* Store the actual directory mode, to be restored
+				 later.
+			      */
+			      current_stat_info.stat = st;
+			      current_mode = mode & ~ current_umask;
+			      current_mode_mask = MODE_RWX;
+			      atflag = AT_SYMLINK_NOFOLLOW;
+			      break;
+			    }
+			  else
+			    {
+			      chmod_error_details (file_name, mode);
+			    }
 			}
+		      break;
 		    }
-		  break;
 		}
 	    }
+	  else if (old_files_option == UNLINK_FIRST_OLD_FILES)
+	    {
+	      status = 0;
+	      break;
+	    }
+	  
 	  errno = EEXIST;
 	}
 
@@ -1978,11 +1985,12 @@ rename_directory (char *src, char *dst)
   else
     {
       int e = errno;
+      bool interdir_made;
 
       switch (e)
 	{
 	case ENOENT:
-	  if (make_directories (dst) == 0)
+	  if (make_directories (dst, &interdir_made) == 0)
 	    {
 	      if (renameat (chdir_fd, src, chdir_fd, dst) == 0)
 		return true;
-- 
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