| Message ID | 20241101133917.27634-5-Jonathan.Cameron@huawei.com |
|---|---|
| State | New |
| Headers | show |
| Series | hw/cxl: Mailbox input parser hardening against invalid input. | expand |
On Fri, Nov 01, 2024 at 01:39:11PM +0000, Jonathan Cameron wrote: > Buggy guest can write a message that advertises more data that > is provided. As QEMU internally duplicates the reported message > size, this may result in an out of bounds access. > Add sanity checks on the size to avoid this. > > Reported-by: Esifiel <esifiel@gmail.com> > Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > --- Reviewed-by: Fan Ni <fan.ni@samsung.com> > hw/cxl/cxl-mailbox-utils.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c > index 3cb499a24f..27fadc4fa8 100644 > --- a/hw/cxl/cxl-mailbox-utils.c > +++ b/hw/cxl/cxl-mailbox-utils.c > @@ -705,6 +705,10 @@ static CXLRetCode cmd_firmware_update_transfer(const struct cxl_cmd *cmd, > } QEMU_PACKED *fw_transfer = (void *)payload_in; > size_t offset, length; > > + if (len < sizeof(*fw_transfer)) { > + return CXL_MBOX_INVALID_PAYLOAD_LENGTH; > + } > + > if (fw_transfer->action == CXL_FW_XFER_ACTION_ABORT) { > /* > * At this point there aren't any on-going transfers > -- > 2.43.0 >
diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c index 3cb499a24f..27fadc4fa8 100644 --- a/hw/cxl/cxl-mailbox-utils.c +++ b/hw/cxl/cxl-mailbox-utils.c @@ -705,6 +705,10 @@ static CXLRetCode cmd_firmware_update_transfer(const struct cxl_cmd *cmd, } QEMU_PACKED *fw_transfer = (void *)payload_in; size_t offset, length; + if (len < sizeof(*fw_transfer)) { + return CXL_MBOX_INVALID_PAYLOAD_LENGTH; + } + if (fw_transfer->action == CXL_FW_XFER_ACTION_ABORT) { /* * At this point there aren't any on-going transfers
Buggy guest can write a message that advertises more data that is provided. As QEMU internally duplicates the reported message size, this may result in an out of bounds access. Add sanity checks on the size to avoid this. Reported-by: Esifiel <esifiel@gmail.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> --- hw/cxl/cxl-mailbox-utils.c | 4 ++++ 1 file changed, 4 insertions(+)