From c40db6d5717023bdd6bb4935161e7ce9678d6234 Mon Sep 17 00:00:00 2001
From: Theodore Ts'o <tytso@mit.edu>
Date: Mon, 25 Oct 1999 21:03:34 +0000
Subject: [PATCH] ChangeLog, pass2.c, problem.c, problem.h:   problem.c,
 problem.h (PR_2_NULL_NAME): Add new problem code.   pass2.c
 (check_dir_block): Require that the length of the directory   	entry be at
 least 12 bytes.  Check to see if the filename is   	zero-length, and flag
 that as an error.

---
 e2fsck/ChangeLog | 8 ++++++++
 e2fsck/pass2.c   | 8 +++++++-
 e2fsck/problem.c | 5 +++++
 e2fsck/problem.h | 3 +++
 4 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/e2fsck/ChangeLog b/e2fsck/ChangeLog
index d4f4dc0c..39f35c2e 100644
--- a/e2fsck/ChangeLog
+++ b/e2fsck/ChangeLog
@@ -1,3 +1,11 @@
+1999-10-25    <tytso@valinux.com>
+
+	* problem.c, problem.h (PR_2_NULL_NAME): Add new problem code.
+
+	* pass2.c (check_dir_block): Require that the length of the
+		directory entry be at least 12 bytes.  Check to see if the
+		filename is zero-length, and flag that as an error.
+
 1999-10-22    <tytso@valinux.com>
 
 	* Release of E2fsprogs 1.16
diff --git a/e2fsck/pass2.c b/e2fsck/pass2.c
index f41cdfef..e6a434cb 100644
--- a/e2fsck/pass2.c
+++ b/e2fsck/pass2.c
@@ -406,7 +406,7 @@ static int check_dir_block(ext2_filsys fs,
 		cd->pctx.dirent = dirent;
 		cd->pctx.num = offset;
 		if (((offset + dirent->rec_len) > fs->blocksize) ||
-		    (dirent->rec_len < 8) ||
+		    (dirent->rec_len < 12) ||
 		    ((dirent->rec_len % 4) != 0) ||
 		    (((dirent->name_len & 0xFF)+8) > dirent->rec_len)) {
 			if (fix_problem(ctx, PR_2_DIR_CORRUPTED, &cd->pctx)) {
@@ -496,6 +496,12 @@ static int check_dir_block(ext2_filsys fs,
 			 * directory hasn't been created yet.
 			 */
 			problem = PR_2_LINK_ROOT;
+		} else if ((dot_state > 2) &&
+			   (dirent->name_len & 0xFF) == 0) {
+			/*
+			 * Don't allow zero-length directory names.
+			 */
+			problem = PR_2_NULL_NAME;
 		}
 
 		if (problem) {
diff --git a/e2fsck/problem.c b/e2fsck/problem.c
index 718002fb..1e26d607 100644
--- a/e2fsck/problem.c
+++ b/e2fsck/problem.c
@@ -708,6 +708,11 @@ static const struct e2fsck_problem problem_table[] = {
 	  "@E has filetype set\n",
 	  PROMPT_CLEAR, PR_PREEN_OK },
 
+	/* Directory filename is null */
+	{ PR_2_NULL_NAME,
+	  "@E has a zero-length name\n",
+	  PROMPT_CLEAR, 0 },
+
 	/* Pass 3 errors */
 
 	/* Pass 3: Checking directory connectivity */
diff --git a/e2fsck/problem.h b/e2fsck/problem.h
index 80b35bee..f9ce29e2 100644
--- a/e2fsck/problem.h
+++ b/e2fsck/problem.h
@@ -420,6 +420,9 @@ struct problem_context {
 /* Directory filetype set when it shouldn't be */
 #define PR_2_CLEAR_FILETYPE	0x020029
 
+/* Directory filename can't be zero-length  */
+#define PR_2_NULL_NAME		0x020030
+
 /*
  * Pass 3 errors
  */