From: "Theodore Y. Ts'o" <tytso@mit.edu>
To: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>,
linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org,
yuanxzhang@fudan.edu.cn, kjlu@umn.edu,
Xin Tan <tanxin.ctf@gmail.com>
Subject: Re: [PATCH] ext4: Fix buffer_head refcnt leak when ext4_iget() fails
Date: Thu, 14 May 2020 10:54:15 -0400 [thread overview]
Message-ID: <20200514145415.GU1596452@mit.edu> (raw)
In-Reply-To: <1587618568-13418-1-git-send-email-xiyuyang19@fudan.edu.cn>
On Thu, Apr 23, 2020 at 01:09:27PM +0800, Xiyu Yang wrote:
> ext4_orphan_get() invokes ext4_read_inode_bitmap(), which returns a
> reference of the specified buffer_head object to "bitmap_bh" with
> increased refcnt.
>
> When ext4_orphan_get() returns, local variable "bitmap_bh" becomes
> invalid, so the refcount should be decreased to keep refcount balanced.
>
> The reference counting issue happens in one exception handling path of
> ext4_orphan_get(). When ext4_iget() fails, the function forgets to
> decrease the refcnt increased by ext4_read_inode_bitmap(), causing a
> refcnt leak.
>
> Fix this issue by calling brelse() when ext4_iget() fails.
>
> Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
> Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Applied, thanks.
- Ted
prev parent reply other threads:[~2020-05-14 14:54 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-23 5:09 [PATCH] ext4: Fix buffer_head refcnt leak when ext4_iget() fails Xiyu Yang
2020-05-14 14:54 ` Theodore Y. Ts'o [this message]
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