From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-la0-f54.google.com ([209.85.215.54]:33026 "EHLO mail-la0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752193AbbBZIz1 (ORCPT ); Thu, 26 Feb 2015 03:55:27 -0500 Received: by labgf13 with SMTP id gf13so9542624lab.0 for ; Thu, 26 Feb 2015 00:55:25 -0800 (PST) From: Rasmus Villemoes To: Bjorn Helgaas Cc: Borislav Petkov , Tony Luck , Rasmus Villemoes , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] PCI/AER: Avoid info leak in __print_tlp_header Date: Thu, 26 Feb 2015 09:55:03 +0100 Message-Id: <1424940903-9147-1-git-send-email-linux@rasmusvillemoes.dk> In-Reply-To: <20150225225859.GB19236@pd.tnic> References: <20150225225859.GB19236@pd.tnic> Sender: linux-pci-owner@vger.kernel.org List-ID: 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 --- 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