configfs: fix config_item refcnt leak in configfs_rmdir()
[ Upstream commit 8aebfffacf
]
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>
5.4-rM2-2.2.x-imx-squashed
parent
2b52a61adb
commit
dcec6678c3
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@ -1519,6 +1519,7 @@ static int configfs_rmdir(struct inode *dir, struct dentry *dentry)
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spin_lock(&configfs_dirent_lock);
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configfs_detach_rollback(dentry);
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spin_unlock(&configfs_dirent_lock);
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config_item_put(parent_item);
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return -EINTR;
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}
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frag->frag_dead = true;
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