From: Prasad J Pandit <p...@fedoraproject.org> While writing a message in 'lsi_do_msgin', message length value in 'msg_len' could be invalid. Add check to avoid OOB access issue.
Signed-off-by: Prasad J Pandit <p...@fedoraproject.org> --- hw/scsi/lsi53c895a.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) Update v1: add .post_load routine and an assert() call -> https://lists.gnu.org/archive/html/qemu-devel/2018-10/msg05730.html diff --git a/hw/scsi/lsi53c895a.c b/hw/scsi/lsi53c895a.c index d1e6534311..3a40e62853 100644 --- a/hw/scsi/lsi53c895a.c +++ b/hw/scsi/lsi53c895a.c @@ -861,12 +861,13 @@ static void lsi_do_status(LSIState *s) static void lsi_do_msgin(LSIState *s) { - int len; + uint8_t len; trace_lsi_do_msgin(s->dbc, s->msg_len); s->sfbr = s->msg[0]; len = s->msg_len; if (len > s->dbc) len = s->dbc; + assert(len <= LSI_MAX_MSGIN_LEN); pci_dma_write(PCI_DEVICE(s), s->dnad, s->msg, len); /* Linux drivers rely on the last byte being in the SIDL. */ s->sidl = s->msg[len - 1]; @@ -2103,11 +2104,23 @@ static int lsi_pre_save(void *opaque) return 0; } +static int lsi_post_load(void *opaque, int version_id) +{ + LSIState *s = opaque; + + if (s->msg_len < 0 || s->msg_len > LSI_MAX_MSGIN_LEN) { + return -EINVAL; + } + + return 0; +} + static const VMStateDescription vmstate_lsi_scsi = { .name = "lsiscsi", .version_id = 0, .minimum_version_id = 0, .pre_save = lsi_pre_save, + .post_load = lsi_post_load, .fields = (VMStateField[]) { VMSTATE_PCI_DEVICE(parent_obj, LSIState), -- 2.17.2
