From 54d68e9333ff65d135faac68fa01be4276f1371f Mon Sep 17 00:00:00 2001
From: Thomas Fitzsimmons <fitzsim@cisco.com>
Date: Wed, 18 Nov 2015 12:42:53 -0500
Subject: [PATCH] fs: ext4: Prevent infinite loop in ext4fs_iterate_dir
If the ext3 journal gets out of sync with what is written on disk, for
example because of an unexpected power cut, ext4fs_read_file can
return an all-zero directory entry. In that case, ext4fs_iterate_dir
would infinite loop.
This patch detects when a directory entry's direntlen member is 0 and
returns a failure status, which breaks out of the infinite loop. As a
result, U-Boot will not find files that may subsequently be recovered
when the journal is replayed.
This is better behaviour than hanging in an infinite loop, but as a
further improvement maybe U-Boot could interpret the ext3 journal and
actually find the unsynced entries.
Signed-off-by: Thomas Fitzsimmons <fitzsim@cisco.com>
Reviewed-by: Stefan Roese <sr@denx.de>
---
fs/ext4/ext4_common.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/fs/ext4/ext4_common.c b/fs/ext4/ext4_common.c
index 727a2f753d..e73223ac22 100644
--- a/fs/ext4/ext4_common.c
+++ b/fs/ext4/ext4_common.c
@@ -1920,6 +1920,11 @@ int ext4fs_iterate_dir(struct ext2fs_node *dir, char *name,
if (status < 0)
return 0;
+ if (dirent.direntlen == 0) {
+ printf("Failed to iterate over directory %s\n", name);
+ return 0;
+ }
+
if (dirent.namelen != 0) {
char filename[dirent.namelen + 1];
struct ext2fs_node *fdiro;
--
2.39.5