diff options
| author | Simon Gaiser <hw42@ipsumj.de> | 2017-10-28 04:53:15 +0200 |
|---|---|---|
| committer | Stefano Stabellini <sstabellini@kernel.org> | 2017-12-14 16:11:53 -0800 |
| commit | 2e63eb2becc228232f12a1ea30a91b2aa8c5cecd (patch) | |
| tree | f6b644baab5e92f9c33850a3b59898e52fc68dc4 | |
| parent | d12c5b7ddf2cee57f3e72fe6f450203a9ab455ed (diff) | |
xen/pt: Set is_express to avoid out-of-bounds write
The passed-through device might be an express device. In this case the
old code allocated a too small emulated config space in
pci_config_alloc() since pci_config_size() returned the size for a
non-express device. This leads to an out-of-bound write in
xen_pt_config_reg_init(), which sometimes results in crashes. So set
is_express as already done for KVM in vfio-pci.
Shortened ASan report:
==17512==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x611000041648 at pc 0x55e0fdac51ff bp 0x7ffe4af07410 sp 0x7ffe4af07408
WRITE of size 2 at 0x611000041648 thread T0
#0 0x55e0fdac51fe in memcpy /usr/include/x86_64-linux-gnu/bits/string3.h:53
#1 0x55e0fdac51fe in stw_he_p include/qemu/bswap.h:330
#2 0x55e0fdac51fe in stw_le_p include/qemu/bswap.h:379
#3 0x55e0fdac51fe in pci_set_word include/hw/pci/pci.h:490
#4 0x55e0fdac51fe in xen_pt_config_reg_init hw/xen/xen_pt_config_init.c:1991
#5 0x55e0fdac51fe in xen_pt_config_init hw/xen/xen_pt_config_init.c:2067
#6 0x55e0fdabcf4d in xen_pt_realize hw/xen/xen_pt.c:830
#7 0x55e0fdf59666 in pci_qdev_realize hw/pci/pci.c:2034
#8 0x55e0fdda7d3d in device_set_realized hw/core/qdev.c:914
[...]
0x611000041648 is located 8 bytes to the right of 256-byte region [0x611000041540,0x611000041640)
allocated by thread T0 here:
#0 0x7ff596a94bb8 in __interceptor_calloc (/usr/lib/x86_64-linux-gnu/libasan.so.4+0xd9bb8)
#1 0x7ff57da66580 in g_malloc0 (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x50580)
#2 0x55e0fdda7d3d in device_set_realized hw/core/qdev.c:914
[...]
Signed-off-by: Simon Gaiser <hw42@ipsumj.de>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
| -rw-r--r-- | hw/xen/xen_pt.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/hw/xen/xen_pt.c b/hw/xen/xen_pt.c index 9bba717708..d57c6d3485 100644 --- a/hw/xen/xen_pt.c +++ b/hw/xen/xen_pt.c @@ -946,6 +946,7 @@ static void xen_pci_passthrough_class_init(ObjectClass *klass, void *data) k->exit = xen_pt_unregister_device; k->config_read = xen_pt_pci_read_config; k->config_write = xen_pt_pci_write_config; + k->is_express = 1; /* We might be */ set_bit(DEVICE_CATEGORY_MISC, dc->categories); dc->desc = "Assign an host PCI device with Xen"; dc->props = xen_pci_passthrough_properties; |