Re: [PATCH v2] livepatch: Reorder to use before freeing a pointer

[Tom Rix]

On 3/23/22 8:53 AM, Petr Mladek wrote:
> On Sat 2022-03-19 18:51:43, trix@xxxxxxxxxx wrote:
> > From: Tom Rix <trix@xxxxxxxxxx>
> >
> > Clang static analysis reports this issue
> > livepatch-shadow-fix1.c:113:2: warning: Use of
> >    memory after it is freed
> >    pr_info("%s: dummy @ %p, prevented leak @ %p\n",
> >    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >
> > The pointer is freed in the previous statement.
> > Reorder the pr_info to report before the free.
> >
> > Similar issue in livepatch-shadow-fix2.c
> I have added the following paragraph:
>
> <snip>
> Note that it is a false positive. pr_info() just prints the address.
> The freed memory is not accessed. Well, the static analyzer could not
> know this easily.
> </snip>
>
> > Signed-off-by: Tom Rix <trix@xxxxxxxxxx>
> and pushed the patch into livepatching/livepatching.git,
> branch for-5.18/selftests-fixes.
>
> IMHO, the patch is so trivial and can be added even in this merge
> window. There is no need to create more dances around it ;-)
>
> Let me know if you disagree. I am going to send the pull request
> on Friday or Monday.

Do whatever is easier for you.  The addition to the commit log is fine.

Thanks

Tom

> Best Regards,
> Petr