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>
This commit is contained in:
Nicholas Kazlauskas 2023-09-13 16:18:44 -04:00 committed by Alex Deucher
parent b85ea95d08
commit 1ffa8602e3
1 changed files with 15 additions and 3 deletions

View File

@ -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;