From: Srinivasan Shanmugam Date: Wed, 7 Feb 2024 04:50:57 +0000 (+0530) Subject: drm/amd/display: Implement bounds check for stream encoder creation in DCN301 X-Git-Tag: v6.6.17~47 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=cd9bd10c59e3c1446680514fd3097c5b00d3712d;p=platform%2Fkernel%2Flinux-starfive.git drm/amd/display: Implement bounds check for stream encoder creation in DCN301 [ Upstream commit 58fca355ad37dcb5f785d9095db5f748b79c5dc2 ] 'stream_enc_regs' array is an array of dcn10_stream_enc_registers structures. The array is initialized with four elements, corresponding to the four calls to stream_enc_regs() in the array initializer. This means that valid indices for this array are 0, 1, 2, and 3. The error message 'stream_enc_regs' 4 <= 5 below, is indicating that there is an attempt to access this array with an index of 5, which is out of bounds. This could lead to undefined behavior Here, eng_id is used as an index to access the stream_enc_regs array. If eng_id is 5, this would result in an out-of-bounds access on the stream_enc_regs array. Thus fixing Buffer overflow error in dcn301_stream_encoder_create reported by Smatch: drivers/gpu/drm/amd/amdgpu/../display/dc/resource/dcn301/dcn301_resource.c:1011 dcn301_stream_encoder_create() error: buffer overflow 'stream_enc_regs' 4 <= 5 Fixes: 3a83e4e64bb1 ("drm/amd/display: Add dcn3.01 support to DC (v2)") Cc: Roman Li Cc: Rodrigo Siqueira Cc: Aurabindo Pillai Signed-off-by: Srinivasan Shanmugam Reviewed-by: Roman Li Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- diff --git a/drivers/gpu/drm/amd/display/dc/dcn301/dcn301_resource.c b/drivers/gpu/drm/amd/display/dc/dcn301/dcn301_resource.c index 79d6697..9485fda 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn301/dcn301_resource.c +++ b/drivers/gpu/drm/amd/display/dc/dcn301/dcn301_resource.c @@ -996,7 +996,7 @@ static struct stream_encoder *dcn301_stream_encoder_create(enum engine_id eng_id vpg = dcn301_vpg_create(ctx, vpg_inst); afmt = dcn301_afmt_create(ctx, afmt_inst); - if (!enc1 || !vpg || !afmt) { + if (!enc1 || !vpg || !afmt || eng_id >= ARRAY_SIZE(stream_enc_regs)) { kfree(enc1); kfree(vpg); kfree(afmt);