ext4: store maxbytes for bitmapped files and return EFBIG as appropriate
Calculate & store the max offset for bitmapped files, and
catch too-large seeks, truncates, and writes in ext4, shortening
or rejecting as appropriate.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 9cf8572..eaace13 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -314,7 +314,10 @@
offsets[n++] = i_block & (ptrs - 1);
final = ptrs;
} else {
- ext4_warning(inode->i_sb, "ext4_block_to_path", "block > big");
+ ext4_warning(inode->i_sb, "ext4_block_to_path",
+ "block %u > max",
+ i_block + direct_blocks +
+ indirect_blocks + double_blocks);
}
if (boundary)
*boundary = final - 1 - (i_block & (ptrs - 1));
@@ -3092,6 +3095,17 @@
ext4_journal_stop(handle);
}
+ if (attr->ia_valid & ATTR_SIZE) {
+ if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)) {
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+
+ if (attr->ia_size > sbi->s_bitmap_maxbytes) {
+ error = -EFBIG;
+ goto err_out;
+ }
+ }
+ }
+
if (S_ISREG(inode->i_mode) &&
attr->ia_valid & ATTR_SIZE && attr->ia_size < inode->i_size) {
handle_t *handle;
