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Date:   Wed, 3 Nov 2021 16:27:10 -0700
From:   Jakub Kicinski <kuba@kernel.org>
To:     Huang Guobin <huangguobin4@huawei.com>
Cc:     <j.vosburgh@gmail.com>, <vfalico@gmail.com>, <andy@greyhouse.net>,
        <davem@davemloft.net>, <netdev@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH -next v2] bonding: Fix a use-after-free problem when
 bond_sysfs_slave_add() failed
Message-ID: <20211103162710.74755593@kicinski-fedora-PC1C0HJN>
In-Reply-To: <1635845853-4259-1-git-send-email-huangguobin4@huawei.com>
References: <1635845853-4259-1-git-send-email-huangguobin4@huawei.com>
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On Tue, 2 Nov 2021 17:37:33 +0800 Huang Guobin wrote:
> When I do fuzz test for bonding device interface, I got the following
> use-after-free Calltrace:

> Put new_slave in bond_sysfs_slave_add() will cause use-after-free problems
> when new_slave is accessed in the subsequent error handling process. Since
> new_slave will be put in the subsequent error handling process, remove the
> unnecessary put to fix it.
> In addition, when sysfs_create_file() fails, if some files have been crea-
> ted successfully, we need to call sysfs_remove_file() to remove them.
> Since there are sysfs_create_files() & sysfs_remove_files() can be used,
> use these two functions instead.
> 
> Fixes: 7afcaec49696 (bonding: use kobject_put instead of _del after kobject_add)
> Signed-off-by: Huang Guobin <huangguobin4@huawei.com>

Reviewed-by: Jakub Kicinski <kuba@kernel.org>