For files where we actually have extent indexes following an extent header (ext_block->eh_depth != 0), the do/while loop from ext4fs_get_extent_block() does not select the proper extent index structure.
For example, if we have:
ext_block->eh_depth = 1 ext_block->eh_entries = 1 fileblock = 0 index[0].ei_block = 0
the do/while loop will exit with i set to 0 and the ext4fs_get_extent_block() function will return 0, even if there was a valid extent index structure following the header.
Signed-off-by: Ionut Nicu ioan.nicu.ext@nsn.com Signed-off-by: Mathias Rulf mathias.rulf@nsn.com --- fs/ext4/ext4_common.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/fs/ext4/ext4_common.c b/fs/ext4/ext4_common.c index 37b6c46..e543478 100644 --- a/fs/ext4/ext4_common.c +++ b/fs/ext4/ext4_common.c @@ -1430,7 +1430,7 @@ static struct ext4_extent_header *ext4fs_get_extent_block i++; if (i >= le16_to_cpu(ext_block->eh_entries)) break; - } while (fileblock > le32_to_cpu(index[i].ei_block)); + } while (fileblock >= le32_to_cpu(index[i].ei_block));
if (--i < 0) return 0;