From: Xiyu Yang xiyuyang19@fudan.edu.cn
[ Upstream commit 8aebfffacfa379ba400da573a5bf9e49634e38cb ]
configfs_rmdir() invokes configfs_get_config_item(), which returns a reference of the specified config_item object to "parent_item" with increased refcnt.
When configfs_rmdir() returns, local variable "parent_item" becomes invalid, so the refcount should be decreased to keep refcount balanced.
The reference counting issue happens in one exception handling path of configfs_rmdir(). When down_write_killable() fails, the function forgets to decrease the refcnt increased by configfs_get_config_item(), causing a refcnt leak.
Fix this issue by calling config_item_put() when down_write_killable() fails.
Signed-off-by: Xiyu Yang xiyuyang19@fudan.edu.cn Signed-off-by: Xin Tan tanxin.ctf@gmail.com Signed-off-by: Christoph Hellwig hch@lst.de Signed-off-by: Sasha Levin sashal@kernel.org --- fs/configfs/dir.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c index c2ef617d2f97..c875f246cb0e 100644 --- a/fs/configfs/dir.c +++ b/fs/configfs/dir.c @@ -1537,6 +1537,7 @@ static int configfs_rmdir(struct inode *dir, struct dentry *dentry) spin_lock(&configfs_dirent_lock); configfs_detach_rollback(dentry); spin_unlock(&configfs_dirent_lock); + config_item_put(parent_item); return -EINTR; } frag->frag_dead = true;