hfsplus: 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.
[hch: port of commit 3d10a15d6919488204bdb264050d156ced20d9aa from hfs]
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@tuxera.com>
diff --git a/fs/hfsplus/brec.c b/fs/hfsplus/brec.c
index c88e5d7..fa90364 100644
--- a/fs/hfsplus/brec.c
+++ b/fs/hfsplus/brec.c
@@ -216,7 +216,7 @@
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;
@@ -235,6 +235,17 @@
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;
@@ -248,6 +259,8 @@
/* panic? */
hfs_bnode_put(node);
hfs_bnode_put(new_node);
+ if (next_node)
+ hfs_bnode_put(next_node);
return ERR_PTR(-ENOSPC);
}
@@ -302,8 +315,7 @@
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);