e2fsprogs: fix endian handling of ext3_extent_header

PATCH New Eric Sandeen 1 participant 1 message Oct 21, 2014

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Eric Sandeen

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2014-10-21 02:36 UTC #0 lore raw

PATCH 1/1 e2fsprogs: fix endian handling of ext3_extent_header

This turned up when trying to resize a filesystem containing a file with many extents on PPC64.

Fix all locations where ext3_extent_header members aren't handled in an endian-safe manner.

Signed-off-by Eric Sandeen <[email protected]>

---

I only audited ext3_extent_header's members, and found places where they were not properly endian-handled.

Is there a reason that disk structures aren't sparse-annotated for endianness? I can't help but wonder if there's a lot more than this lurking.

lib/ext2fs/ext3_extents.h +10 -5

index 4163436..a18d705 100644
@@ -106,15 +106,20 @@ struct ext3_ext_path {
 	((struct ext3_extent_idx *) (((char *) (__hdr__)) +	\
 				     sizeof(struct ext3_extent_header)))
 #define EXT_HAS_FREE_INDEX(__path__) \
-	((__path__)->p_hdr->eh_entries < (__path__)->p_hdr->eh_max)
+	(ext2fs_le16_to_cpu((__path__)->p_hdr->eh_entries) < \
+	 ext2fs_le16_to_cpu((__path__)->p_hdr->eh_max))
 #define EXT_LAST_EXTENT(__hdr__) \
-	(EXT_FIRST_EXTENT((__hdr__)) + (__hdr__)->eh_entries - 1)
+	(EXT_FIRST_EXTENT((__hdr__)) + \
+	ext2fs_le16_to_cpu((__hdr__)->eh_entries) - 1)
 #define EXT_LAST_INDEX(__hdr__) \
-	(EXT_FIRST_INDEX((__hdr__)) + (__hdr__)->eh_entries - 1)
+	(EXT_FIRST_INDEX((__hdr__)) + \
+	ext2fs_le16_to_cpu((__hdr__)->eh_entries) - 1)
 #define EXT_MAX_EXTENT(__hdr__) \
-	(EXT_FIRST_EXTENT((__hdr__)) + (__hdr__)->eh_max - 1)
+	(EXT_FIRST_EXTENT((__hdr__)) + \
+	ext2fs_le16_to_cpu((__hdr__)->eh_max) - 1)
 #define EXT_MAX_INDEX(__hdr__) \
-	(EXT_FIRST_INDEX((__hdr__)) + (__hdr__)->eh_max - 1)
+	(EXT_FIRST_INDEX((__hdr__)) + \
+	ext2fs_le16_to_cpu((__hdr__)->eh_max) - 1)
 
 #endif /* _LINUX_EXT3_EXTENTS */

lib/ext2fs/inline_data.c +1 -1

index 7eb8b94..8167b76 100644
@@ -420,7 +420,7 @@ ext2fs_inline_data_file_expand(ext2_filsys fs, ext2_ino_t ino,
 		eh = (struct ext3_extent_header *) &inode->i_block[0];
 		eh->eh_depth = 0;
 		eh->eh_entries = 0;
-		eh->eh_magic = EXT3_EXT_MAGIC;
+		eh->eh_magic = ext2fs_cpu_to_le16(EXT3_EXT_MAGIC);
 		i = (sizeof(inode->i_block) - sizeof(*eh)) /
 			sizeof(struct ext3_extent);
 		eh->eh_max = ext2fs_cpu_to_le16(i);