Messages in this thread |  | | | Subject | Re: [PATCH 1/1] NET: netpoll, fix potential NULL ptr dereference | | From | Matt Mackall <> | | Date | Tue, 16 Mar 2010 12:12:07 -0500 |
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On Tue, 2010-03-16 at 16:29 +0100, Jiri Slaby wrote: > Stanse found that one error path in netpoll_setup dereferences npinfo > even though it is NULL. Avoid that by adding new label and go to that > instead. > > Signed-off-by: Jiri Slaby <jslaby@suse.cz> > Cc: Daniel Borkmann <danborkmann@googlemail.com> > Cc: David S. Miller <davem@davemloft.net> > --- > net/core/netpoll.c | 4 ++-- > 1 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/net/core/netpoll.c b/net/core/netpoll.c > index 7aa6972..d4ec38f 100644 > --- a/net/core/netpoll.c > +++ b/net/core/netpoll.c > @@ -735,7 +735,7 @@ int netpoll_setup(struct netpoll *np) > npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); > if (!npinfo) { > err = -ENOMEM; > - goto release; > + goto put; > } > > npinfo->rx_flags = 0; > @@ -845,7 +845,7 @@ int netpoll_setup(struct netpoll *np) > > kfree(npinfo); > } > - > +put: > dev_put(ndev); > return err; > }
I don't get it. The source of the branch tests for !ndev->npinfo and the original destination of the branch also tests for !ndev->npinfo. I don't see how it gets dereferenced.
This looks like it just patches over a false positive in your tool (which isn't correlating the validity of npinfo with ndev->npinfo) without actually improving the code. However, it seems that we can drop the second check at release if we add your new exit point.
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