From: Al Viro Date: Sun, 16 Mar 2008 22:48:08 +0000 (+0000) Subject: hfs_bnode_find() can fail, resulting in hfs_bnode_split() breakage X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=3d10a15d6919488204bdb264050d156ced20d9aa;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git 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: Al Viro Signed-off-by: Linus Torvalds --- diff --git a/fs/hfs/brec.c b/fs/hfs/brec.c index 878bf25dbc6a..92fb358ce824 100644 --- a/fs/hfs/brec.c +++ b/fs/hfs/brec.c @@ -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);