Date:   Tue, 4 Jan 2022 08:37:27 +0100
From:   Greg KH <gregkh@linuxfoundation.org>
To:     Li Fei1 <fei1.li@intel.com>
Cc:     Zhou Qingyang <zhou1615@umn.edu>, kjlu@umn.edu,
        reinette.chatre@intel.com, zhi.a.wang@intel.com,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] virt: acrn: fix a memory leak bug in acrn_dev_ioctl()
Message-ID: <YdP5N3lYqF09dLPv@kroah.com>
References: <20220104024729.GA26952@louislifei-OptiPlex-7050>
 <20220104034501.45715-1-zhou1615@umn.edu>
 <20220104035032.GA27848@louislifei-OptiPlex-7050>
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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.
> > 
> 
> Signed-off-by: Fei Li <fei1.li@intel.com>

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