ext4: refactor __ext4_check_dir_entry() to accept start and size
The __ext4_check_dir_entry() function() is used to check whether the
de is over the block boundary. Now with inline data, it could be
within the block boundary while exceeds the inode size. So check this
function to check the overflow more precisely.
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index edb9f10..10da2d5 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -892,6 +892,7 @@
EXT4_DIR_REC_LEN(0));
for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
if (ext4_check_dir_entry(dir, NULL, de, bh,
+ bh->b_data, bh->b_size,
(block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
+ ((char *)de - bh->b_data))) {
/* On error, skip the f_pos to the next block. */
@@ -1130,7 +1131,8 @@
if ((char *) de + namelen <= dlimit &&
ext4_match (namelen, name, de)) {
/* found a match - just to be sure, do a full check */
- if (ext4_check_dir_entry(dir, NULL, de, bh, offset))
+ if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data,
+ bh->b_size, offset))
return -1;
*res_dir = de;
return 1;
@@ -1643,7 +1645,8 @@
de = (struct ext4_dir_entry_2 *)bh->b_data;
top = bh->b_data + (blocksize - csum_size) - reclen;
while ((char *) de <= top) {
- if (ext4_check_dir_entry(dir, NULL, de, bh, offset))
+ if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data,
+ bh->b_size, offset))
return -EIO;
if (ext4_match(namelen, name, de))
return -EEXIST;
@@ -2076,7 +2079,8 @@
pde = NULL;
de = (struct ext4_dir_entry_2 *) bh->b_data;
while (i < bh->b_size - csum_size) {
- if (ext4_check_dir_entry(dir, NULL, de, bh, i))
+ if (ext4_check_dir_entry(dir, NULL, de, bh,
+ bh->b_data, bh->b_size, i))
return -EIO;
if (de == de_del) {
BUFFER_TRACE(bh, "get_write_access");
@@ -2439,7 +2443,8 @@
set_buffer_verified(bh);
de = (struct ext4_dir_entry_2 *) bh->b_data;
}
- if (ext4_check_dir_entry(inode, NULL, de, bh, offset)) {
+ if (ext4_check_dir_entry(inode, NULL, de, bh,
+ bh->b_data, bh->b_size, offset)) {
de = (struct ext4_dir_entry_2 *)(bh->b_data +
sb->s_blocksize);
offset = (offset | (sb->s_blocksize - 1)) + 1;