From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bartlomiej Zolnierkiewicz Subject: [PATCH] libata: add missing NULL pointer check to ata_eh_reset() Date: Sun, 26 Jul 2009 16:21:01 +0200 Message-ID: <200907261621.01893.bzolnier@gmail.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT Return-path: Received: from mail-bw0-f228.google.com ([209.85.218.228]:60242 "EHLO mail-bw0-f228.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751076AbZGYO0U convert rfc822-to-8bit (ORCPT ); Sat, 25 Jul 2009 10:26:20 -0400 Content-Disposition: inline Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: jgarzik@pobox.com Cc: linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org, Dan Carpenter , corbet@lwn.net, eteo@redhat.com From: Bartlomiej Zolnierkiewicz Subject: [PATCH] libata: add missing NULL pointer check to ata_eh_reset() >>From Dan's list: drivers/ata/libata-eh.c +2403 ata_eh_reset(80) warning: variable derefenced before check 'slave' Please note that this is _not_ a real bug at the moment since ata_eh_context structure is embedded into ata_list structure and the code alwas checks for 'slave' before accessing 'sehc'. Anyway lets add missing check and always have a valid 'sehc' pointer (which makes code easier to understand and prevents introducing some possible bugs in the future). Reported-by: Dan Carpenter Cc: corbet@lwn.net Cc: eteo@redhat.com Signed-off-by: Bartlomiej Zolnierkiewicz --- drivers/ata/libata-eh.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Index: b/drivers/ata/libata-eh.c =================================================================== --- a/drivers/ata/libata-eh.c +++ b/drivers/ata/libata-eh.c @@ -2329,7 +2329,7 @@ int ata_eh_reset(struct ata_link *link, struct ata_port *ap = link->ap; struct ata_link *slave = ap->slave_link; struct ata_eh_context *ehc = &link->eh_context; - struct ata_eh_context *sehc = &slave->eh_context; + struct ata_eh_context *sehc = slave ? &slave->eh_context : NULL; unsigned int *classes = ehc->classes; unsigned int lflags = link->flags; int verbose = !(ehc->i.flags & ATA_EHI_QUIET);