| Message ID | 20200604113525.58898-1-ppandit@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | pci: assert configuration access is within bounds | expand |
On Thu, Jun 04, 2020 at 05:05:25PM +0530, P J P wrote: > From: Prasad J Pandit <pjp@fedoraproject.org> > > While accessing PCI configuration bytes, assert that > 'address + len' is within PCI configuration space. > > Generally it is within bounds. This is more of a defensive > assert, in case a buggy device was to send 'address' which > may go out of bounds. > > Suggested-by: Philippe Mathieu-Daudé <philmd@redhat.com> > Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> > --- > hw/pci/pci.c | 4 ++++ > 1 file changed, 4 insertions(+) > > Update v1: defensive assert as separate patch > -> https://lists.gnu.org/archive/html/qemu-devel/2020-06/msg00957.html > -> https://lists.gnu.org/archive/html/qemu-devel/2020-06/msg00960.html > > diff --git a/hw/pci/pci.c b/hw/pci/pci.c > index 70c66965f5..7bf2ae6d92 100644 > --- a/hw/pci/pci.c > +++ b/hw/pci/pci.c > @@ -1381,6 +1381,8 @@ uint32_t pci_default_read_config(PCIDevice *d, > { > uint32_t val = 0; > > + assert(address + len <= pci_config_size(d)); > + > if (pci_is_express_downstream_port(d) && > ranges_overlap(address, len, d->exp.exp_cap + PCI_EXP_LNKSTA, 2)) { > pcie_sync_bridge_lnk(d); > @@ -1394,6 +1396,8 @@ void pci_default_write_config(PCIDevice *d, uint32_t addr, uint32_t val_in, int > int i, was_irq_disabled = pci_irq_disabled(d); > uint32_t val = val_in; > > + assert(addr + l <= pci_config_size(d)); > + > for (i = 0; i < l; val >>= 8, ++i) { > uint8_t wmask = d->wmask[addr + i]; > uint8_t w1cmask = d->w1cmask[addr + i]; > -- > 2.26.2
* P J P (ppandit@redhat.com) wrote: > From: Prasad J Pandit <pjp@fedoraproject.org> > > While accessing PCI configuration bytes, assert that > 'address + len' is within PCI configuration space. > > Generally it is within bounds. This is more of a defensive > assert, in case a buggy device was to send 'address' which > may go out of bounds. Can a guest trigger this assert? Dave > Suggested-by: Philippe Mathieu-Daudé <philmd@redhat.com> > Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org> > --- > hw/pci/pci.c | 4 ++++ > 1 file changed, 4 insertions(+) > > Update v1: defensive assert as separate patch > -> https://lists.gnu.org/archive/html/qemu-devel/2020-06/msg00957.html > -> https://lists.gnu.org/archive/html/qemu-devel/2020-06/msg00960.html > > diff --git a/hw/pci/pci.c b/hw/pci/pci.c > index 70c66965f5..7bf2ae6d92 100644 > --- a/hw/pci/pci.c > +++ b/hw/pci/pci.c > @@ -1381,6 +1381,8 @@ uint32_t pci_default_read_config(PCIDevice *d, > { > uint32_t val = 0; > > + assert(address + len <= pci_config_size(d)); > + > if (pci_is_express_downstream_port(d) && > ranges_overlap(address, len, d->exp.exp_cap + PCI_EXP_LNKSTA, 2)) { > pcie_sync_bridge_lnk(d); > @@ -1394,6 +1396,8 @@ void pci_default_write_config(PCIDevice *d, uint32_t addr, uint32_t val_in, int > int i, was_irq_disabled = pci_irq_disabled(d); > uint32_t val = val_in; > > + assert(addr + l <= pci_config_size(d)); > + > for (i = 0; i < l; val >>= 8, ++i) { > uint8_t wmask = d->wmask[addr + i]; > uint8_t w1cmask = d->w1cmask[addr + i]; > -- > 2.26.2 > > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
On Thu, Jun 04, 2020 at 05:36:31PM +0100, Dr. David Alan Gilbert wrote: > * P J P (ppandit@redhat.com) wrote: > > From: Prasad J Pandit <pjp@fedoraproject.org> > > > > While accessing PCI configuration bytes, assert that > > 'address + len' is within PCI configuration space. > > > > Generally it is within bounds. This is more of a defensive > > assert, in case a buggy device was to send 'address' which > > may go out of bounds. > > Can a guest trigger this assert? > > Dave Shouldn't be able to, no. > > Suggested-by: Philippe Mathieu-Daudé <philmd@redhat.com> > > Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org> > > --- > > hw/pci/pci.c | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > Update v1: defensive assert as separate patch > > -> https://lists.gnu.org/archive/html/qemu-devel/2020-06/msg00957.html > > -> https://lists.gnu.org/archive/html/qemu-devel/2020-06/msg00960.html > > > > diff --git a/hw/pci/pci.c b/hw/pci/pci.c > > index 70c66965f5..7bf2ae6d92 100644 > > --- a/hw/pci/pci.c > > +++ b/hw/pci/pci.c > > @@ -1381,6 +1381,8 @@ uint32_t pci_default_read_config(PCIDevice *d, > > { > > uint32_t val = 0; > > > > + assert(address + len <= pci_config_size(d)); > > + > > if (pci_is_express_downstream_port(d) && > > ranges_overlap(address, len, d->exp.exp_cap + PCI_EXP_LNKSTA, 2)) { > > pcie_sync_bridge_lnk(d); > > @@ -1394,6 +1396,8 @@ void pci_default_write_config(PCIDevice *d, uint32_t addr, uint32_t val_in, int > > int i, was_irq_disabled = pci_irq_disabled(d); > > uint32_t val = val_in; > > > > + assert(addr + l <= pci_config_size(d)); > > + > > for (i = 0; i < l; val >>= 8, ++i) { > > uint8_t wmask = d->wmask[addr + i]; > > uint8_t w1cmask = d->w1cmask[addr + i]; > > -- > > 2.26.2 > > > > > -- > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
diff --git a/hw/pci/pci.c b/hw/pci/pci.c index 70c66965f5..7bf2ae6d92 100644 --- a/hw/pci/pci.c +++ b/hw/pci/pci.c @@ -1381,6 +1381,8 @@ uint32_t pci_default_read_config(PCIDevice *d, { uint32_t val = 0; + assert(address + len <= pci_config_size(d)); + if (pci_is_express_downstream_port(d) && ranges_overlap(address, len, d->exp.exp_cap + PCI_EXP_LNKSTA, 2)) { pcie_sync_bridge_lnk(d); @@ -1394,6 +1396,8 @@ void pci_default_write_config(PCIDevice *d, uint32_t addr, uint32_t val_in, int int i, was_irq_disabled = pci_irq_disabled(d); uint32_t val = val_in; + assert(addr + l <= pci_config_size(d)); + for (i = 0; i < l; val >>= 8, ++i) { uint8_t wmask = d->wmask[addr + i]; uint8_t w1cmask = d->w1cmask[addr + i];