Commit 3d10a15d authored by Al Viro's avatar Al Viro Committed by Linus Torvalds
Browse files

hfs_bnode_find() can fail, resulting in hfs_bnode_split() breakage 



oops and fs corruption; the latter can happen even on valid fs in case of oom.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent a978b30a

fs/hfs/brec.c

+15 −3
Original line number Diff line number Diff line
@@ -229,7 +229,7 @@ skip: 
static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd)

{

	struct hfs_btree *tree;

	struct hfs_bnode *node, *new_node;

	struct hfs_bnode *node, *new_node, *next_node;

	struct hfs_bnode_desc node_desc;

	int num_recs, new_rec_off, new_off, old_rec_off;

	int data_start, data_end, size;
@@ -248,6 +248,17 @@ static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd) 
	new_node->type = node->type;

	new_node->height = node->height;



	if (node->next)

		next_node = hfs_bnode_find(tree, node->next);

	else

		next_node = NULL;



	if (IS_ERR(next_node)) {

		hfs_bnode_put(node);

		hfs_bnode_put(new_node);

		return next_node;

	}



	size = tree->node_size / 2 - node->num_recs * 2 - 14;

	old_rec_off = tree->node_size - 4;

	num_recs = 1;
@@ -261,6 +272,8 @@ static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd) 
		/* panic? */

		hfs_bnode_put(node);

		hfs_bnode_put(new_node);

		if (next_node)

			hfs_bnode_put(next_node);

		return ERR_PTR(-ENOSPC);

	}
@@ -315,8 +328,7 @@ static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd) 
	hfs_bnode_write(node, &node_desc, 0, sizeof(node_desc));



	/* update next bnode header */

	if (new_node->next) {

		struct hfs_bnode *next_node = hfs_bnode_find(tree, new_node->next);

	if (next_node) {

		next_node->prev = new_node->this;

		hfs_bnode_read(next_node, &node_desc, 0, sizeof(node_desc));

		node_desc.prev = cpu_to_be32(next_node->prev);