From: Leon Romanovsky <leon@kernel.org>
To: xiyuyang19@fudan.edu.cn
Cc: yuanxzhang@fudan.edu.cn, kjlu@umn.edu,
Xin Tan <tanxin.ctf@gmail.com>,
Faisal Latif <faisal.latif@intel.com>,
Shiraz Saleem <shiraz.saleem@intel.com>,
Doug Ledford <dledford@redhat.com>,
Jason Gunthorpe <jgg@ziepe.ca>,
linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] infiniband: i40iw: fix a potential NULL pointer dereference
Date: Thu, 26 Dec 2019 10:14:27 +0200 [thread overview]
Message-ID: <20191226081427.GA6285@unreal> (raw)
In-Reply-To: <1577328772-14038-1-git-send-email-xiyuyang19@fudan.edu.cn>
On Thu, Dec 26, 2019 at 10:52:52AM +0800, xiyuyang19@fudan.edu.cn wrote:
> From: Xiyu Yang <xiyuyang19@fudan.edu.cn>
>
> in_dev_get may return a NULL object. The fix handles the situation
> by adding a check to avoid NULL pointer dereference on idev,
> as pick_local_ipaddrs does.
>
> Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
> Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
> ---
> drivers/infiniband/hw/i40iw/i40iw_main.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/infiniband/hw/i40iw/i40iw_main.c b/drivers/infiniband/hw/i40iw/i40iw_main.c
> index d44cf33d..18587cc 100644
> --- a/drivers/infiniband/hw/i40iw/i40iw_main.c
> +++ b/drivers/infiniband/hw/i40iw/i40iw_main.c
> @@ -1225,6 +1225,8 @@ static void i40iw_add_ipv4_addr(struct i40iw_device *iwdev)
> const struct in_ifaddr *ifa;
>
> idev = in_dev_get(dev);
> + if (!idev)
> + return;
1. You forgot to release rtnl lock.
2. The rtnl_trylock()/rtnl_unlock() scheme is wrong in this function.
That lock is global and any devices can take it and prevent from i40iw
to success in rtnl_trylock(), after that in_dev_for_each_ifa_rtnl() will
be incorrect.
> in_dev_for_each_ifa_rtnl(ifa, idev) {
> i40iw_debug(&iwdev->sc_dev, I40IW_DEBUG_CM,
> "IP=%pI4, vlan_id=%d, MAC=%pM\n", &ifa->ifa_address,
> --
> 2.7.4
>
prev parent reply other threads:[~2019-12-26 8:14 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-26 2:52 [PATCH] infiniband: i40iw: fix a potential NULL pointer dereference xiyuyang19
2019-12-26 8:14 ` Leon Romanovsky [this message]
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