Re: [PATCH] platform/x86: alienware-wmi: fix kfree on potentially uninitialized pointer

From: Darren Hart
Date: Wed Apr 03 2019 - 18:26:35 EST


On Wed, Apr 03, 2019 at 11:05:12PM +0100, Colin Ian King wrote:
> On 03/04/2019 23:02, Darren Hart wrote:
> > On Sat, Mar 30, 2019 at 12:17:12AM +0000, Colin King wrote:
> >> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> >>
> >> Currently the kfree of output.pointer can be potentially freeing
> >> an uninitalized pointer in the case where out_data is NULL. Fix this
> >> by reworking the case where out_data is not-null to perform the
> >> ACPI status check and also the kfree of outpoint.pointer in one block
> >> and hence ensuring the pointer is only freed when it has been used.
> >>
> >> Also replace the if (ptr != NULL) idiom with just if (ptr).
> >>
> >> Fixes: ff0e9f26288d ("platform/x86: alienware-wmi: Correct a memory leak")
> >> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> >
> > Thanks for the catch Colin, queued for testing.
> >
> > Did you trigger this error or detect it via review or static analysis?
> >
> Static analysis, I'm now running a licensed version of Coverity on one
> of our servers.

We typically include the tool used to identify such bugs, and I see several such
tags for Coverity in the logs. Was there a reason not to include that tag? If
just an oversight, can you provide that tag and I'll amend the commit.

--
Darren Hart
VMware Open Source Technology Center