From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:38933) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QmKwN-0005fg-Hu for qemu-devel@nongnu.org; Thu, 28 Jul 2011 03:23:32 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QmKwM-0001Aa-BC for qemu-devel@nongnu.org; Thu, 28 Jul 2011 03:23:31 -0400 Received: from mail.valinux.co.jp ([210.128.90.3]:47896) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QmKwL-00019z-LM for qemu-devel@nongnu.org; Thu, 28 Jul 2011 03:23:30 -0400 Date: Thu, 28 Jul 2011 16:23:24 +0900 From: Isaku Yamahata Message-ID: <20110728072324.GF14976@valinux.co.jp> References: <4E2858C2.5050909@siemens.com> <20110722052707.GA8241@redhat.com> <4E293D3D.8070904@siemens.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4E293D3D.8070904@siemens.com> Subject: Re: [Qemu-devel] [PATCH v2] pci: Common overflow prevention List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka Cc: qemu-devel , "Michael S. Tsirkin" This might be a bit late comment... On Fri, Jul 22, 2011 at 11:05:01AM +0200, Jan Kiszka wrote: > diff --git a/hw/pci_host.c b/hw/pci_host.c > index 728e2d4..bfdc321 100644 > --- a/hw/pci_host.c > +++ b/hw/pci_host.c > @@ -47,17 +47,33 @@ static inline PCIDevice *pci_dev_find_by_addr(PCIBus *bus, uint32_t addr) > return pci_find_device(bus, bus_num, devfn); > } > > +void pci_config_write_common(PCIDevice *pci_dev, uint32_t addr, > + uint32_t limit, uint32_t val, uint32_t len) > +{ > + assert(len <= 4); > + pci_dev->config_write(pci_dev, addr, val, MIN(len, limit - addr)); > +} > + > +uint32_t pci_config_read_common(PCIDevice *pci_dev, uint32_t addr, > + uint32_t limit, uint32_t len) > +{ > + assert(len <= 4); > + return pci_dev->config_read(pci_dev, addr, MIN(len, limit - addr)); > +} > + Since limit and addr is unsigned, MIN(len, limit - addr) = len if limit < addr. So we need explicit "if (limit < addr) return;". Here's the patch for pci branch. >>From 75c1a2b47c93ad987cd7a37fb62bda9a59f27948 Mon Sep 17 00:00:00 2001 Message-Id: <75c1a2b47c93ad987cd7a37fb62bda9a59f27948.1311837763.git.yamahata@valinux.co.jp> From: Isaku Yamahata Date: Thu, 28 Jul 2011 16:20:28 +0900 Subject: [PATCH] pci/host: limit check of pci_host_config_read/write_common This patch adds boundary check in pci_host_config_read/write_common() Since limit and addr is unsigned, MIN(len, limit - addr) = len if limit < addr. So we need explicit "if (limit <= addr) return;" Signed-off-by: Isaku Yamahata --- hw/pci_host.c | 6 ++++++ 1 files changed, 6 insertions(+), 0 deletions(-) diff --git a/hw/pci_host.c b/hw/pci_host.c index 2e8a29f..71fd3a1 100644 --- a/hw/pci_host.c +++ b/hw/pci_host.c @@ -51,6 +51,9 @@ void pci_host_config_write_common(PCIDevice *pci_dev, uint32_t addr, uint32_t limit, uint32_t val, uint32_t len) { assert(len <= 4); + if (limit <= addr) { + return; + } pci_dev->config_write(pci_dev, addr, val, MIN(len, limit - addr)); } @@ -58,6 +61,9 @@ uint32_t pci_host_config_read_common(PCIDevice *pci_dev, uint32_t addr, uint32_t limit, uint32_t len) { assert(len <= 4); + if (limit <= addr) { + return 0; + } return pci_dev->config_read(pci_dev, addr, MIN(len, limit - addr)); } -- 1.7.1.1 -- yamahata