Hi Dmitry,
On 13/9/23 12:10, Dmitry Frolov wrote:
According to cxl_interleave_ways_enc(),
fw->num_targets is allowed to be up to 16.
This also corresponds to CXL specs.
So, the fw->target_hbs[] array is iterated from 0 to 15.
But it is staticaly declared of length 8.
"statically"
Thus, out of bound array access may occur.
Fixes: c28db9e000 ("hw/pci-bridge: Make PCIe and CXL PXB Devices inherit from
TYPE_PXB_DEV")
Signed-off-by: Dmitry Frolov <fro...@swemel.ru>
---
include/hw/cxl/cxl.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/hw/cxl/cxl.h b/include/hw/cxl/cxl.h
index 56c9e7676e..4944725849 100644
--- a/include/hw/cxl/cxl.h
+++ b/include/hw/cxl/cxl.h
@@ -29,7 +29,7 @@ typedef struct PXBCXLDev PXBCXLDev;
typedef struct CXLFixedWindow {
uint64_t size;
char **targets;
- PXBCXLDev *target_hbs[8];
+ PXBCXLDev *target_hbs[16];
uint8_t num_targets;
uint8_t enc_int_ways;
uint8_t enc_int_gran;
The loop in cxl_fixed_memory_window_config() is indeed unsafe.
OOB can be catched adding:
-- >8 --
diff --git a/hw/cxl/cxl-host.c b/hw/cxl/cxl-host.c
index 034c7805b3..fe9143409b 100644
--- a/hw/cxl/cxl-host.c
+++ b/hw/cxl/cxl-host.c
@@ -33,6 +33,7 @@ static void cxl_fixed_memory_window_config(CXLState
*cxl_state,
for (target = object->targets; target; target = target->next) {
fw->num_targets++;
}
+ assert(fw->num_targets <= ARRAY_SIZE(fw->target_hbs));
fw->enc_int_ways = cxl_interleave_ways_enc(fw->num_targets, errp);
if (*errp) {
---
If Jonathan concurs, please add to your patch.
Thanks,
Phil.
