From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ob0-f179.google.com ([209.85.214.179]:46476 "EHLO mail-ob0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754846AbbCFSdy (ORCPT ); Fri, 6 Mar 2015 13:33:54 -0500 Received: by obcva2 with SMTP id va2so3792213obc.13 for ; Fri, 06 Mar 2015 10:33:53 -0800 (PST) Date: Fri, 6 Mar 2015 12:33:51 -0600 From: Bjorn Helgaas To: Rasmus Villemoes Cc: Borislav Petkov , Tony Luck , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] PCI/AER: Avoid info leak in __print_tlp_header Message-ID: <20150306183351.GG20077@google.com> References: <20150225225859.GB19236@pd.tnic> <1424940903-9147-1-git-send-email-linux@rasmusvillemoes.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1424940903-9147-1-git-send-email-linux@rasmusvillemoes.dk> Sender: linux-pci-owner@vger.kernel.org List-ID: On Thu, Feb 26, 2015 at 09:55:03AM +0100, Rasmus Villemoes wrote: > Commit fab4c256a58b ("PCI/AER: Add a TLP header print helper") > introduced the helper function __print_tlp_header, but contrary to the > intention, the behaviour did change: Since we're taking the address of > the parameter t, the first 4 or 8 bytes printed will be the value of > the pointer t itself, and the remaining 12 or 8 bytes will be > who-knows-what (something from the stack). > > We want to show the values of the four members of the struct > aer_header_log_regs; that can be done without ugly and error-prone > casts. On little-endian this should produce the same output as > originally intended, and since no-one has complained about getting > garbage output so far, I think big-endian should be ok too. > > Fixes: fab4c256a58b ("PCI/AER: Add a TLP header print helper") > Signed-off-by: Rasmus Villemoes Applied with Borislav's ack to for-linus for v4.0, thanks! Also added stable tag. > --- > v2: Just print ->dwX as-is. > > drivers/pci/pcie/aer/aerdrv_errprint.c | 12 ++---------- > 1 file changed, 2 insertions(+), 10 deletions(-) > > diff --git a/drivers/pci/pcie/aer/aerdrv_errprint.c b/drivers/pci/pcie/aer/aerdrv_errprint.c > index c6849d9e86ce..167fe411ce2e 100644 > --- a/drivers/pci/pcie/aer/aerdrv_errprint.c > +++ b/drivers/pci/pcie/aer/aerdrv_errprint.c > @@ -132,16 +132,8 @@ static const char *aer_agent_string[] = { > static void __print_tlp_header(struct pci_dev *dev, > struct aer_header_log_regs *t) > { > - unsigned char *tlp = (unsigned char *)&t; > - > - dev_err(&dev->dev, " TLP Header:" > - " %02x%02x%02x%02x %02x%02x%02x%02x" > - " %02x%02x%02x%02x %02x%02x%02x%02x\n", > - *(tlp + 3), *(tlp + 2), *(tlp + 1), *tlp, > - *(tlp + 7), *(tlp + 6), *(tlp + 5), *(tlp + 4), > - *(tlp + 11), *(tlp + 10), *(tlp + 9), > - *(tlp + 8), *(tlp + 15), *(tlp + 14), > - *(tlp + 13), *(tlp + 12)); > + dev_err(&dev->dev, " TLP Header: %08x %08x %08x %08x\n", > + t->dw0, t->dw1, t->dw2, t->dw3); > } > > static void __aer_print_error(struct pci_dev *dev, > -- > 2.1.3 >