From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54956) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z5DpC-0002Hm-EK for qemu-devel@nongnu.org; Wed, 17 Jun 2015 09:56:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z5Dp8-0006Q4-Dv for qemu-devel@nongnu.org; Wed, 17 Jun 2015 09:56:18 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37380) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z5Dp8-0006Pz-97 for qemu-devel@nongnu.org; Wed, 17 Jun 2015 09:56:14 -0400 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (Postfix) with ESMTPS id 01D2C33B365 for ; Wed, 17 Jun 2015 13:56:12 +0000 (UTC) Message-ID: <55817C77.80408@redhat.com> Date: Wed, 17 Jun 2015 15:56:07 +0200 From: Laszlo Ersek MIME-Version: 1.0 References: <1434545105-5811-1-git-send-email-lersek@redhat.com> <1434545105-5811-6-git-send-email-lersek@redhat.com> <20150617154603-mutt-send-email-mst@redhat.com> In-Reply-To: <20150617154603-mutt-send-email-mst@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v6 5/7] hw/core: rebase sysbus_get_fw_dev_path() to g_strdup_printf() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: Marcel Apfelbaum , qemu-devel@nongnu.org, Markus Armbruster On 06/17/15 15:46, Michael S. Tsirkin wrote: > On Wed, Jun 17, 2015 at 02:45:03PM +0200, Laszlo Ersek wrote: >> This is done mainly for improving readability, and in preparation for the >> next patch, but Markus pointed out another bonus for the string being >> returned: >> >> "No arbitrary length limit. Before the patch, it's 39 characters, and the >> code breaks catastrophically when qdev_fw_name() is longer: the second >> snprintf() is called with its first argument pointing beyond path[], and >> its second argument underflowing to a huge size." >> >> Cc: Markus Armbruster >> Cc: Marcel Apfelbaum >> Cc: Michael S. Tsirkin >> Signed-off-by: Laszlo Ersek >> Tested-by: Marcel Apfelbaum >> Reviewed-by: Marcel Apfelbaum >> Reviewed-by: Markus Armbruster > > Reviewed-by: Michael S. Tsirkin > > In fact, I'd Cc stable on this one. Will do, thanks. Laszlo > >> --- >> >> Notes: >> v6: >> - no changes >> >> v5: >> - separate "%s@" from TARGET_FMT_plx with a space [Markus] >> - copied Markus's note about "no arbitrary length limit" on the retval >> into the commit message >> >> v4: >> - unchanged >> >> v3: >> - new in v3 >> >> hw/core/sysbus.c | 16 ++++++---------- >> 1 file changed, 6 insertions(+), 10 deletions(-) >> >> diff --git a/hw/core/sysbus.c b/hw/core/sysbus.c >> index b53c351..92eced9 100644 >> --- a/hw/core/sysbus.c >> +++ b/hw/core/sysbus.c >> @@ -281,19 +281,15 @@ static void sysbus_dev_print(Monitor *mon, DeviceState *dev, int indent) >> static char *sysbus_get_fw_dev_path(DeviceState *dev) >> { >> SysBusDevice *s = SYS_BUS_DEVICE(dev); >> - char path[40]; >> - int off; >> - >> - off = snprintf(path, sizeof(path), "%s", qdev_fw_name(dev)); >> >> if (s->num_mmio) { >> - snprintf(path + off, sizeof(path) - off, "@"TARGET_FMT_plx, >> - s->mmio[0].addr); >> - } else if (s->num_pio) { >> - snprintf(path + off, sizeof(path) - off, "@i%04x", s->pio[0]); >> + return g_strdup_printf("%s@" TARGET_FMT_plx, qdev_fw_name(dev), >> + s->mmio[0].addr); >> } >> - >> - return g_strdup(path); >> + if (s->num_pio) { >> + return g_strdup_printf("%s@i%04x", qdev_fw_name(dev), s->pio[0]); >> + } >> + return g_strdup(qdev_fw_name(dev)); >> } >> >> void sysbus_add_io(SysBusDevice *dev, hwaddr addr, >> -- >> 1.8.3.1 >>