Re: [PATCH -next,v2 1/2] audit: fix possible null-pointer dereference in audit_filter_rules

[cuigaosheng]

Thanks for your review, and i have droped the redundant commit message 
and add a Fixes tag to the patch.

https://patchwork.kernel.org/project/linux-audit/patch/20211016072351.237745-2-cuigaosheng1@xxxxxxxxxx/ 
<https://patchwork.kernel.org/project/linux-audit/patch/20211016072351.237745-2-cuigaosheng1@xxxxxxxxxx/>

Gaosheng.

在 2021/10/14 5:12, Paul Moore 写道:
> On Wed, Oct 13, 2021 at 5:10 AM Gaosheng Cui <cuigaosheng1@xxxxxxxxxx> wrote:
> > Fix this possible null-pointer dereference in audit_filter_rules.
> Thanks for fixing this, just a couple of small comments:
>
> I think you can drop the description text below here, the code snippet
> is just a duplicate of the code and the error message is pretty
> obvious.
>
> > If ctx is null, a null-pointer dereference will occur:
> >      case AUDIT_SADDR_FAM:
> >          if (ctx->sockaddr)
> >                  ...
> >          break;
> >
> > audit_filter_rules() error: we previously assumed 'ctx' could be null
> >
> > Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> > Signed-off-by: Gaosheng Cui <cuigaosheng1@xxxxxxxxxx>
> I would also add a Fixes tag, for example:
>
> Fixes: bf361231c295 ("audit: add saddr_fam filter field")
>
> > ---
> >   kernel/auditsc.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> > index 4ba3b8573ff4..42d4a4320526 100644
> > --- a/kernel/auditsc.c
> > +++ b/kernel/auditsc.c
> > @@ -647,7 +647,7 @@ static int audit_filter_rules(struct task_struct *tsk,
> >                          result = audit_comparator(audit_loginuid_set(tsk), f->op, f->val);
> >                          break;
> >                  case AUDIT_SADDR_FAM:
> > -                       if (ctx->sockaddr)
> > +                       if (ctx && ctx->sockaddr)
> >                                  result = audit_comparator(ctx->sockaddr->ss_family,
> >                                                            f->op, f->val);
> >                          break;
> > --
> > 2.30.0