6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Nicholas Kazlauskas <nicholas.kazlauskas@xxxxxxx>
commit 1ffa8602e39b89469dc703ebab7a7e44c33da0f7 upstream.
[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>
Tested-by: Daniel Wheeler <daniel.wheeler@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c | 18 +++++++++++++++---
1 file changed, 15 insertions(+), 3 deletions(-)
--- a/drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c
+++ b/drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c
@@ -658,9 +658,16 @@ enum dmub_status dmub_srv_sync_inbox1(st
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;
@@ -694,6 +701,11 @@ enum dmub_status dmub_srv_cmd_queue(stru
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;
