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[1/1,SRU,Jammy] drm/amd/display: Fix out of bounds access on DNC31 stream encoder regs

Message ID 20220118194429.2234874-2-vicamo.yang@canonical.com
State New
Headers show
Series Fix AMD Yellow Carp GPU UBSAN warning array-index-out-of-bounds | expand

Commit Message

You-Sheng Yang Jan. 18, 2022, 7:44 p.m. UTC 
From: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>

BugLink: https://bugs.launchpad.net/bugs/1958229

[Why]
During dcn31_stream_encoder_create, if PHYC/D get remapped to F/G on B0
then we'll index 5 or 6 into a array of length 5 - leading to an
access violation on some configs during device creation.

[How]
Software won't be touching PHYF/PHYG directly, so just extend the
array to cover all possible engine IDs.

Even if it does by try to access one of these registers by accident
the offset will be 0 and we'll get a warning during the access.

Fixes: 2fe9a0e1173f ("drm/amd/display: Fix DCN3 B0 DP Alt Mapping")
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit d374d3b493215d637b9e7be12a93f22caf4c1f97)
Signed-off-by: You-Sheng Yang <vicamo.yang@canonical.com>
---
 drivers/gpu/drm/amd/display/dc/dcn31/dcn31_resource.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_resource.c b/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_resource.c
index dc670886fb89..0698eb1d9039 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_resource.c
@@ -470,7 +470,8 @@  static const struct dcn30_afmt_mask afmt_mask = {
 	SE_DCN3_REG_LIST(id)\
 }
 
-static const struct dcn10_stream_enc_registers stream_enc_regs[] = {
+/* Some encoders won't be initialized here - but they're logical, not physical. */
+static const struct dcn10_stream_enc_registers stream_enc_regs[ENGINE_ID_COUNT] = {
 	stream_enc_regs(0),
 	stream_enc_regs(1),
 	stream_enc_regs(2),