[linux-next:master 2996/11714] drivers/gpu/drm/amd/amdgpu/../display/dc/dcn303/dcn303_resource.c:531 dcn303_stream_encoder_create() warn: possible memory leak of 'enc1'

[linux-next:master 2996/11714] drivers/gpu/drm/amd/amdgpu/../display/dc/dcn303/dcn303_resource.c:531 dcn303_stream_encoder_create() warn: possible memory leak of 'enc1'

[Dan Carpenter]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head:   889bab4c367a0ef58208fd80fafa74bb6e2dca26
commit: cd6d421e3d1ad5926b74091254e345db730e7706 [2996/11714] drm/amd/display: Initial DC support for Beige Goby
config: i386-randconfig-m021-20210622 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>

smatch warnings:
drivers/gpu/drm/amd/amdgpu/../display/dc/dcn303/dcn303_resource.c:531 dcn303_stream_encoder_create() warn: possible memory leak of 'enc1'
drivers/gpu/drm/amd/amdgpu/../display/dc/dcn303/dcn303_resource.c:533 dcn303_stream_encoder_create() error: buffer overflow 'stream_enc_regs' 2 <= 4

vim +/enc1 +531 drivers/gpu/drm/amd/amdgpu/../display/dc/dcn303/dcn303_resource.c

cd6d421e3d1ad5 Aurabindo Pillai 2021-03-15  511  static struct stream_encoder *dcn303_stream_encoder_create(enum engine_id eng_id, struct dc_context *ctx)
cd6d421e3d1ad5 Aurabindo Pillai 2021-03-15  512  {
cd6d421e3d1ad5 Aurabindo Pillai 2021-03-15  513  	struct dcn10_stream_encoder *enc1;
cd6d421e3d1ad5 Aurabindo Pillai 2021-03-15  514  	struct vpg *vpg;
cd6d421e3d1ad5 Aurabindo Pillai 2021-03-15  515  	struct afmt *afmt;
cd6d421e3d1ad5 Aurabindo Pillai 2021-03-15  516  	int vpg_inst;
cd6d421e3d1ad5 Aurabindo Pillai 2021-03-15  517  	int afmt_inst;
cd6d421e3d1ad5 Aurabindo Pillai 2021-03-15  518  
cd6d421e3d1ad5 Aurabindo Pillai 2021-03-15  519  	/* Mapping of VPG, AFMT, DME register blocks to DIO block instance */
cd6d421e3d1ad5 Aurabindo Pillai 2021-03-15  520  	if (eng_id <= ENGINE_ID_DIGE) {

"eng_id" can be 4 here.

cd6d421e3d1ad5 Aurabindo Pillai 2021-03-15  521  		vpg_inst = eng_id;
cd6d421e3d1ad5 Aurabindo Pillai 2021-03-15  522  		afmt_inst = eng_id;
cd6d421e3d1ad5 Aurabindo Pillai 2021-03-15  523  	} else
cd6d421e3d1ad5 Aurabindo Pillai 2021-03-15  524  		return NULL;
cd6d421e3d1ad5 Aurabindo Pillai 2021-03-15  525  
cd6d421e3d1ad5 Aurabindo Pillai 2021-03-15  526  	enc1 = kzalloc(sizeof(struct dcn10_stream_encoder), GFP_KERNEL);
cd6d421e3d1ad5 Aurabindo Pillai 2021-03-15  527  	vpg = dcn303_vpg_create(ctx, vpg_inst);
cd6d421e3d1ad5 Aurabindo Pillai 2021-03-15  528  	afmt = dcn303_afmt_create(ctx, afmt_inst);
cd6d421e3d1ad5 Aurabindo Pillai 2021-03-15  529  
cd6d421e3d1ad5 Aurabindo Pillai 2021-03-15  530  	if (!enc1 || !vpg || !afmt)
cd6d421e3d1ad5 Aurabindo Pillai 2021-03-15 @531  		return NULL;

Leaks.

cd6d421e3d1ad5 Aurabindo Pillai 2021-03-15  532  
cd6d421e3d1ad5 Aurabindo Pillai 2021-03-15 @533  	dcn30_dio_stream_encoder_construct(enc1, ctx, ctx->dc_bios, eng_id, vpg, afmt, &stream_enc_regs[eng_id],

stream_enc_regs[] is a two element array.

cd6d421e3d1ad5 Aurabindo Pillai 2021-03-15  534  			&se_shift, &se_mask);
cd6d421e3d1ad5 Aurabindo Pillai 2021-03-15  535  
cd6d421e3d1ad5 Aurabindo Pillai 2021-03-15  536  	return &enc1->base;
cd6d421e3d1ad5 Aurabindo Pillai 2021-03-15  537  }

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