Commit 3f9d6b86 authored Jan 22, 2021 by zhangyi (F) Committed by Zheng Zengkai Feb 08, 2021

jffs2: move jffs2_init_inode_info() just after allocating inode



hulk inclusion
category: bugfix
bugzilla: 47443
CVE: NA
---------------------------

After commit 4fdcfab5 ("jffs2: fix use-after-free on symlink
traversal"), it expose a freeing uninitialized memory problem due to
this commit move the operaion of freeing f->target to
jffs2_i_callback(), which may not be initialized in some error path of
allocating jffs2 inode (eg: jffs2_iget()->iget_locked()->
destroy_inode()->..->jffs2_i_callback()->kfree(f->target)).

Fix this by initialize the jffs2_inode_info just after allocating it.

Reported-by: Guohua Zhong <zhongguohua1@huawei.com>
Reported-by: Huaijie Yi <yihuaijie@huawei.com>
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Reviewed-by: Yang Erkun <yangerkun@huawei.com>
[backport from hulk-4.4]
Signed-off-by: yangerkun <yangerkun@huawei.com>
Reviewed-by: zhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>

parent a7d48da7

fs/jffs2/fs.c

+0 −2

Original line number	Diff line number	Diff line
		@@ -270,7 +270,6 @@ struct inode jffs2_iget(struct super_block sb, unsigned long ino)
		f = JFFS2_INODE_INFO(inode);
		c = JFFS2_SB_INFO(inode->i_sb);

		jffs2_init_inode_info(f);
		mutex_lock(&f->sem);

		ret = jffs2_do_read_inode(c, f, inode->i_ino, &latest_node);
		@@ -438,7 +437,6 @@ struct inode jffs2_new_inode (struct inode dir_i, umode_t mode, struct jffs2_r
		return ERR_PTR(-ENOMEM);

		f = JFFS2_INODE_INFO(inode);
		jffs2_init_inode_info(f);
		mutex_lock(&f->sem);

		memset(ri, 0, sizeof(*ri));

fs/jffs2/super.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -42,6 +42,8 @@ static struct inode jffs2_alloc_inode(struct super_block sb)
		f = kmem_cache_alloc(jffs2_inode_cachep, GFP_KERNEL);
		if (!f)
		return NULL;

		jffs2_init_inode_info(f);
		return &f->vfs_inode;
		}