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authorNicholas Kazlauskas <nicholas.kazlauskas@amd.com>2023-09-13 16:18:44 -0400
committerAlex Deucher <alexander.deucher@amd.com>2023-11-17 00:46:01 -0500
commit1ffa8602e39b89469dc703ebab7a7e44c33da0f7 (patch)
tree59f1617450516c4813a547a49963249042a6823f
parentb85ea95d086471afb4ad062012a4d73cd328fa86 (diff)
downloadlinux-1ffa8602e39b89469dc703ebab7a7e44c33da0f7.tar.gz
drm/amd/display: Guard against invalid RPTR/WPTR being set
[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@amd.com> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org Reviewed-by: Hansen Dsouza <hansen.dsouza@amd.com> Acked-by: Alex Hung <alex.hung@amd.com> Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com> Tested-by: Daniel Wheeler <daniel.wheeler@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
-rw-r--r--drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c18
1 files 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 e43e8d4bfe375e..5d36f3e5dc2bd0 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;