diff options
| author | Harry Wentland <harry.wentland@amd.com> | 2026-05-07 16:26:31 -0400 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2026-05-19 12:13:56 -0400 |
| commit | 6c92f6d9600efa3ef0d9e560a2b52776d9803c29 (patch) | |
| tree | bd38d029a944075b28c0aa92517b25ef960d3e7f /drivers/gpu | |
| parent | 86d2b20644b11d21fe52c596e6e922b4590a3e3f (diff) | |
drm/amd/display: Validate payload length and link_index in dc_process_dmub_aux_transfer_async
[Why&How]
dc_process_dmub_aux_transfer_async() copies payload->length bytes into a
16-byte stack buffer (dpaux.data[16]) guarded only by an ASSERT(), which
is a no-op in release builds. If a caller ever passes length > 16 this
results in a stack buffer overflow via memcpy.
Additionally, link_index is used to dereference dc->links[] without
bounds checking against dc->link_count, risking an out-of-bounds access.
Replace the ASSERT with a hard runtime check that returns false when
payload->length exceeds the destination buffer size, and add a bounds
check for link_index before it is used.
Assisted-by: GitHub Copilot:Claude claude-4-opus
Reviewed-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Ivan Lipski <ivan.lipski@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit ba4caa9fecdf7a38f98c878ad05a8a64148b6881)
Cc: stable@vger.kernel.org
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/amd/display/dc/core/dc.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c index 419f894c87b0..b3530fbf32f7 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc.c @@ -6071,7 +6071,11 @@ bool dc_process_dmub_aux_transfer_async(struct dc *dc, uint8_t action; union dmub_rb_cmd cmd = {0}; - ASSERT(payload->length <= 16); + if (link_index >= dc->link_count || !dc->links[link_index]) + return false; + + if (payload->length > sizeof(cmd.dp_aux_access.aux_control.dpaux.data)) + return false; cmd.dp_aux_access.header.type = DMUB_CMD__DP_AUX_ACCESS; cmd.dp_aux_access.header.payload_bytes = 0; |