From: Nicholas Kazlauskas <nicholas.kazlauskas@xxxxxxx>
[WHY]
HW can return invalid values on register read, guard against these being
set and causing us to access memory out of range and page fault.
[HOW]
Guard at sync_inbox1 and guard at pushing commands.
Cc: Mario Limonciello <mario.limonciello@xxxxxxx>
Cc: Alex Deucher <alexander.deucher@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Hansen Dsouza <hansen.dsouza@xxxxxxx>
Acked-by: Alex Hung <alex.hung@xxxxxxx>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@xxxxxxx>
---
.../gpu/drm/amd/display/dmub/src/dmub_srv.c | 18 +++++++++++++++---
1 file changed, 15 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c b/drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c
index e43e8d4bfe37..5d36f3e5dc2b 100644
--- a/drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c
+++ b/drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c
@@ -707,9 +707,16 @@ enum dmub_status dmub_srv_sync_inbox1(struct dmub_srv *dmub)
return DMUB_STATUS_INVALID;
if (dmub->hw_funcs.get_inbox1_rptr && dmub->hw_funcs.get_inbox1_wptr) {
- dmub->inbox1_rb.rptr = dmub->hw_funcs.get_inbox1_rptr(dmub);
- dmub->inbox1_rb.wrpt = dmub->hw_funcs.get_inbox1_wptr(dmub);
- dmub->inbox1_last_wptr = dmub->inbox1_rb.wrpt;
+ uint32_t rptr = dmub->hw_funcs.get_inbox1_rptr(dmub);
+ uint32_t wptr = dmub->hw_funcs.get_inbox1_wptr(dmub);
+
+ if (rptr > dmub->inbox1_rb.capacity || wptr > dmub->inbox1_rb.capacity) {
+ return DMUB_STATUS_HW_FAILURE;
+ } else {
+ dmub->inbox1_rb.rptr = rptr;
+ dmub->inbox1_rb.wrpt = wptr;
+ dmub->inbox1_last_wptr = dmub->inbox1_rb.wrpt;
+ }
}
return DMUB_STATUS_OK;
@@ -743,6 +750,11 @@ enum dmub_status dmub_srv_cmd_queue(struct dmub_srv *dmub,
if (!dmub->hw_init)
return DMUB_STATUS_INVALID;
+ if (dmub->inbox1_rb.rptr > dmub->inbox1_rb.capacity ||
+ dmub->inbox1_rb.wrpt > dmub->inbox1_rb.capacity) {
+ return DMUB_STATUS_HW_FAILURE;
+ }
+
if (dmub_rb_push_front(&dmub->inbox1_rb, cmd))
return DMUB_STATUS_OK;
--
2.42.0
