Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756615Ab2HGUvQ (ORCPT ); Tue, 7 Aug 2012 16:51:16 -0400 Received: from 1010ds2-suoe.0.fullrate.dk ([90.184.90.115]:16940 "EHLO swampdragon.chaosbits.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756328Ab2HGUu6 (ORCPT ); Tue, 7 Aug 2012 16:50:58 -0400 Date: Tue, 7 Aug 2012 22:50:56 +0200 (CEST) From: Jesper Juhl To: linux-kernel@vger.kernel.org cc: tpmdd-devel@lists.sourceforge.net, Sirrix AG , Marcel Selhorst , Rajiv Andrade , Kent Yoder , Seiji Munetoh , Stefan Berger , Reiner Sailer , Kylene Hall Subject: [PATCH] tpm: Do not dereference NULL pointer if acpi_os_map_memory() fails. Message-ID: User-Agent: Alpine 2.00 (LNX 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1600 Lines: 48 In drivers/char/tpm/tpm_bios.c::read_log() we call acpi_os_map_memory(). That call may fail for a number of reasons (invallid address, out of memory etc). If the call fails it returns NULL and we just pass that to memcpy() unconditionally, which will go bad when it tries to dereference the pointer. Unfortunately we just get NULL back, so we can't really tell the user exactely what went wrong, but we can at least avoid crashing and return an error (-EIO seemed more generic and more suitable here than -ENOMEM or something else, so I picked that). Signed-off-by: Jesper Juhl --- drivers/char/tpm/tpm_bios.c | 5 +++++ 1 file changed, 5 insertions(+) Compile tested only. diff --git a/drivers/char/tpm/tpm_bios.c b/drivers/char/tpm/tpm_bios.c index 0636520..0c5c274 100644 --- a/drivers/char/tpm/tpm_bios.c +++ b/drivers/char/tpm/tpm_bios.c @@ -410,6 +410,11 @@ static int read_log(struct tpm_bios_log *log) log->bios_event_log_end = log->bios_event_log + len; virt = acpi_os_map_memory(start, len); + if (!virt) { + printk("%s: ERROR - Unable to map memory\n", + __func__); + return -EIO; + } memcpy(log->bios_event_log, virt, len); -- 1.7.11.4 -- Jesper Juhl http://www.chaosbits.net/ Don't top-post http://www.catb.org/jargon/html/T/top-post.html Plain text mails only, please. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/