On Thu, Jul 28, 2011 at 11:40:21AM +0300, Michael S. Tsirkin wrote: > On Thu, Jul 28, 2011 at 04:23:24PM +0900, Isaku Yamahata wrote: > > 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.yamah...@valinux.co.jp> > > From: Isaku Yamahata <yamah...@valinux.co.jp> > > 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 <yamah...@valinux.co.jp> > > I don't see a problem with this, but could you please clarify when does > this happen? I think this is only possible for a pci device > behind an express root. If so, this belongs in pcie_host.c
Right. I'll move the check into pcie_host.c -- yamahata