From 10a7a1b8babbdd5684684da31482eab1931316f0 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Stefan=20Br=C3=BCns?= Date: Tue, 6 Sep 2016 04:36:45 +0200 Subject: ext4: Avoid corruption of directories with hash tree indexes MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit While directories can be read using the old linear scan method, adding a new file would require updating the index tree (alternatively, the whole tree could be removed). Signed-off-by: Stefan Brüns Reviewed-by: Lukasz Majewski --- fs/ext4/ext4_write.c | 5 +++++ include/ext4fs.h | 1 + 2 files changed, 6 insertions(+) diff --git a/fs/ext4/ext4_write.c b/fs/ext4/ext4_write.c index a52804e8e1..8554793f4f 100644 --- a/fs/ext4/ext4_write.c +++ b/fs/ext4/ext4_write.c @@ -881,6 +881,11 @@ int ext4fs_write(const char *fname, unsigned char *buffer, goto fail; if (ext4fs_iget(parent_inodeno, g_parent_inode)) goto fail; + /* do not mess up a directory using hash trees */ + if (le32_to_cpu(g_parent_inode->flags) & EXT4_INDEX_FL) { + printf("hash tree directory\n"); + goto fail; + } /* check if the filename is already present in root */ existing_file_inodeno = ext4fs_filename_unlink(filename); if (existing_file_inodeno != -1) { diff --git a/include/ext4fs.h b/include/ext4fs.h index e3f6216fa9..6e31c73812 100644 --- a/include/ext4fs.h +++ b/include/ext4fs.h @@ -28,6 +28,7 @@ #define __EXT4__ #include +#define EXT4_INDEX_FL 0x00001000 /* Inode uses hash tree index */ #define EXT4_EXTENTS_FL 0x00080000 /* Inode uses extents */ #define EXT4_EXT_MAGIC 0xf30a #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM 0x0010 -- cgit v1.2.3