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

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

[hch: port of commit 3d10a15d69 from hfs]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@tuxera.com>
This commit is contained in:
Al Viro 2010-10-14 09:53:42 -04:00 committed by Christoph Hellwig
parent ee52716245
commit b6b41424f0
1 changed files with 15 additions and 3 deletions
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18
fs/hfsplus/brec.c
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@ -216,7 +216,7 @@ int hfs_brec_remove(struct hfs_find_data *fd)
static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd) static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd)
{ {
struct hfs_btree *tree; struct hfs_btree *tree;
struct hfs_bnode *node, *new_node; struct hfs_bnode *node, *new_node, *next_node;
struct hfs_bnode_desc node_desc; struct hfs_bnode_desc node_desc;
int num_recs, new_rec_off, new_off, old_rec_off; int num_recs, new_rec_off, new_off, old_rec_off;
int data_start, data_end, size; int data_start, data_end, size;
@ -235,6 +235,17 @@ static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd)
new_node->type = node->type; new_node->type = node->type;
new_node->height = node->height; 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; size = tree->node_size / 2 - node->num_recs * 2 - 14;
old_rec_off = tree->node_size - 4; old_rec_off = tree->node_size - 4;
num_recs = 1; num_recs = 1;
@ -248,6 +259,8 @@ static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd)
/* panic? */ /* panic? */
hfs_bnode_put(node); hfs_bnode_put(node);
hfs_bnode_put(new_node); hfs_bnode_put(new_node);
if (next_node)
hfs_bnode_put(next_node);
return ERR_PTR(-ENOSPC); return ERR_PTR(-ENOSPC);
} }
@ -302,8 +315,7 @@ static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd)
hfs_bnode_write(node, &node_desc, 0, sizeof(node_desc)); hfs_bnode_write(node, &node_desc, 0, sizeof(node_desc));
/* update next bnode header */ /* update next bnode header */
if (new_node->next) { if (next_node) {
struct hfs_bnode *next_node = hfs_bnode_find(tree, new_node->next);
next_node->prev = new_node->this; next_node->prev = new_node->this;
hfs_bnode_read(next_node, &node_desc, 0, sizeof(node_desc)); hfs_bnode_read(next_node, &node_desc, 0, sizeof(node_desc));
node_desc.prev = cpu_to_be32(next_node->prev); node_desc.prev = cpu_to_be32(next_node->prev);