Unverified Commit 5f1e8ffb authored by openeuler-ci-bot's avatar openeuler-ci-bot Committed by Gitee
Browse files

!10978 CVE-2024-42304 

Merge Pull Request from: @ci-robot 
 
PR sync from: Yifan Qiao <qiaoyifan4@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/7EHPDVTF5IYPNOM2ENWOQOOQUEXSR3XD/ 
Baokun Li (2):
  ext4: check dot and dotdot of dx_root before making dir indexed
  ext4: make sure the first directory block is not a hole


-- 
2.39.2
 
https://gitee.com/src-openeuler/kernel/issues/IAKQB7 
 
Link:https://gitee.com/openeuler/kernel/pulls/10978

 

Reviewed-by: default avatarLiu YongQiang <liuyongqiang13@huawei.com>
Signed-off-by: default avatarZhang Changzhong <zhangchangzhong@huawei.com>
parents 772b88c8 aafafc72

fs/ext4/namei.c

+57 −16
Original line number Diff line number Diff line
@@ -146,10 +146,11 @@ static struct buffer_head *__ext4_read_dirblock(struct inode *inode, 


		return bh;

	}

	if (!bh && (type == INDEX || type == DIRENT_HTREE)) {

	/* The first directory block must not be a hole. */

	if (!bh && (type == INDEX || type == DIRENT_HTREE || block == 0)) {

		ext4_error_inode(inode, func, line, block,

				 "Directory hole found for htree %s block",

				 (type == INDEX) ? "index" : "leaf");

				 "Directory hole found for htree %s block %u",

				 (type == INDEX) ? "index" : "leaf", block);

		return ERR_PTR(-EFSCORRUPTED);

	}

	if (!bh)
@@ -1986,6 +1987,52 @@ static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname, 
	return 0;

}



static bool ext4_check_dx_root(struct inode *dir, struct dx_root *root)

{

	struct fake_dirent *fde;

	const char *error_msg;

	unsigned int rlen;

	unsigned int blocksize = dir->i_sb->s_blocksize;

	char *blockend = (char *)root + dir->i_sb->s_blocksize;



	fde = &root->dot;

	if (unlikely(fde->name_len != 1)) {

		error_msg = "invalid name_len for '.'";

		goto corrupted;

	}

	if (unlikely(strncmp(root->dot_name, ".", fde->name_len))) {

		error_msg = "invalid name for '.'";

		goto corrupted;

	}

	rlen = ext4_rec_len_from_disk(fde->rec_len, blocksize);

	if (unlikely((char *)fde + rlen >= blockend)) {

		error_msg = "invalid rec_len for '.'";

		goto corrupted;

	}



	fde = &root->dotdot;

	if (unlikely(fde->name_len != 2)) {

		error_msg = "invalid name_len for '..'";

		goto corrupted;

	}

	if (unlikely(strncmp(root->dotdot_name, "..", fde->name_len))) {

		error_msg = "invalid name for '..'";

		goto corrupted;

	}

	rlen = ext4_rec_len_from_disk(fde->rec_len, blocksize);

	if (unlikely((char *)fde + rlen >= blockend)) {

		error_msg = "invalid rec_len for '..'";

		goto corrupted;

	}



	return true;



corrupted:

	EXT4_ERROR_INODE(dir, "Corrupt dir, %s, running e2fsck is recommended",

			 error_msg);

	return false;

}



/*

 * This converts a one block unindexed directory to a 3 block indexed

 * directory, and adds the dentry to the indexed directory.
@@ -2020,17 +2067,17 @@ static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname, 
		brelse(bh);

		return retval;

	}



	root = (struct dx_root *) bh->b_data;

	if (!ext4_check_dx_root(dir, root)) {

		brelse(bh);

		return -EFSCORRUPTED;

	}



	/* The 0th block becomes the root, move the dirents out */

	fde = &root->dotdot;

	de = (struct ext4_dir_entry_2 *)((char *)fde +

		ext4_rec_len_from_disk(fde->rec_len, blocksize));

	if ((char *) de >= (((char *) root) + blocksize)) {

		EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");

		brelse(bh);

		return -EFSCORRUPTED;

	}

	len = ((char *) root) + (blocksize - csum_size) - (char *) de;



	/* Allocate new block for the 0th block's dirents */
@@ -2804,10 +2851,7 @@ bool ext4_empty_dir(struct inode *inode) 
		EXT4_ERROR_INODE(inode, "invalid size");

		return false;

	}

	/* The first directory block must not be a hole,

	 * so treat it as DIRENT_HTREE

	 */

	bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE);

	bh = ext4_read_dirblock(inode, 0, EITHER);

	if (IS_ERR(bh))

		return false;
@@ -3387,10 +3431,7 @@ static struct buffer_head *ext4_get_first_dir_block(handle_t *handle, 
		struct ext4_dir_entry_2 *de;

		unsigned int offset;



		/* The first directory block must not be a hole, so

		 * treat it as DIRENT_HTREE

		 */

		bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE);

		bh = ext4_read_dirblock(inode, 0, EITHER);

		if (IS_ERR(bh)) {

			*retval = PTR_ERR(bh);

			return NULL;