Date:   Tue, 4 Jan 2022 16:09:02 +0800
From:   Li Fei1 <fei1.li@intel.com>
To:     zhou1615@umn.edu, kjlu@umn.edu, reinette.chatre@intel.com,
        zhi.a.wang@intel.com, gregkh@linuxfoundation.org,
        linux-kernel@vger.kernel.org, fei1.li@intel.com
Subject: Re: [PATCH] virt: acrn: fix a memory leak bug in acrn_dev_ioctl()
Message-ID: <20220104080902.GA7254@louislifei-OptiPlex-7050>
References: <20220104024729.GA26952@louislifei-OptiPlex-7050>
 <20220104034501.45715-1-zhou1615@umn.edu>
 <20220104035032.GA27848@louislifei-OptiPlex-7050>
 <YdP5N3lYqF09dLPv@kroah.com>
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On Tue, Jan 04, 2022 at 08:37:27AM +0100, Greg KH wrote:
> On Tue, Jan 04, 2022 at 11:50:33AM +0800, Li Fei1 wrote:
> > On Tue, Jan 04, 2022 at 11:45:01AM +0800, Zhou Qingyang wrote:
> > > In acrn_dev_ioctl(), vm_param is not released or passed out on the 
> > > error path of "if ((vm_param->reserved0 | vm_param->reserved1) != 0)", 
> > > which could lead to a memory leak.
> > > 
> > > Fix this bug by adding a kfree of vm_param on the error path.
> > > 
> > > This bug was found by a static analyzer.
> > > 
> > > Builds with CONFIG_ACRN_GUEST=y, CONFIG_ACRN_HSM=y show no new warnings, 
> > > and our static analyzer no longer warns about this code.
> > > 
> > > Fixes: 9c5137aedd11 (“9c5137aedd11 virt: acrn: Introduce VM management interfaces”)
> > > Signed-off-by: Zhou Qingyang <zhou1615@umn.edu>
> > > ---
> > > The analysis employs differential checking to identify inconsistent
> > > security operations (e.g., checks or kfrees) between two code paths
> > > and confirms that the inconsistent operations are not recovered in 
> > > the current function or the callers, so they constitute bugs. 
> > > 
> > > Note that, as a bug found by static analysis, it can be a false
> > > positive or hard to trigger. Multiple researchers have cross-reviewed
> > > the bug.
> > > 
> > > Changes in v2:
> > >   -  Fix the same bug in ACRN_IOCTL_SET_VCPU_REGS.
Hi Qingyang

I think the "Changes in v2" was not fixes the code in commit "9c5137aedd11 virt: acrn: Introduce VM management interfaces", but in commit 2ad2aaee1bc9 "virt: acrn: Introduce an ioctl to set vCPU registers state".
Would you please to split this patch into two and please replace “...” with "..." in your commit message.

Thanks.


> > > 
> > 
> > Signed-off-by: Fei Li <fei1.li@intel.com>
Please ignore my "Signed-off" here. Sorry.
> 
> For the multiple obvious reasons (not the least being you didn't even
> run it through our normal testing scripts), I am not going to take this
> change, sorry.
> 
> Fei, please be more careful in the future.
> 
> greg k-h