From: Prasad J Pandit <p...@fedoraproject.org> While reading PCI configuration bytes, a guest may send an address towards the end of the configuration space. It may lead to an OOB access issue. Add check to ensure 'address + size' is within PCI configuration space.
Reported-by: Ren Ding <rd...@gatech.edu> Reported-by: Hanqing Zhao <hanq...@gatech.edu> Reported-by: Yi Ren <c4t...@gmail.com> Suggested-by: BALATON Zoltan <bala...@eik.bme.hu> Signed-off-by: Prasad J Pandit <p...@fedoraproject.org> --- hw/display/ati.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) Update v3: avoid modifying 'addr' variable -> https://lists.gnu.org/archive/html/qemu-devel/2020-06/msg00834.html diff --git a/hw/display/ati.c b/hw/display/ati.c index 67604e68de..b4d0fd88b7 100644 --- a/hw/display/ati.c +++ b/hw/display/ati.c @@ -387,7 +387,9 @@ static uint64_t ati_mm_read(void *opaque, hwaddr addr, unsigned int size) val = s->regs.crtc_pitch; break; case 0xf00 ... 0xfff: - val = pci_default_read_config(&s->dev, addr - 0xf00, size); + if ((addr - 0xf00) + size <= pci_config_size(&s->dev)) { + val = pci_default_read_config(&s->dev, addr - 0xf00, size); + } break; case CUR_OFFSET: val = s->regs.cur_offset; -- 2.26.2