An issue was identified in the dcn21_link_encoder_create function where an out-of-bounds access could occur when the hpd_source index was used to reference the link_enc_hpd_regs array. This array has a fixed size and the index was not being checked against the array's bounds before accessing it. This fix adds a conditional check to ensure that the hpd_source index is within the valid range of the link_enc_hpd_regs array. If the index is out of bounds, the function now returns NULL to prevent undefined behavior. The conditional check ensures that the hpd_source index is greater than or equal to HPD_SOURCEID1 and less than HPD_SOURCEID_COUNT, which corresponds to the valid range of indices for the array. References: [ 65.920507] ------------[ cut here ]------------ [ 65.920510] UBSAN: array-index-out-of-bounds in drivers/gpu/drm/amd/amdgpu/../display/dc/resource/dcn21/dcn21_resource.c:1312:29 [ 65.920519] index 7 is out of range for type 'dcn10_link_enc_hpd_registers [5]' [ 65.920523] CPU: 3 PID: 1178 Comm: modprobe Tainted: G OE 6.8.0-cleanershaderfeatureresetasdntipmi200nv2132 #13 [ 65.920525] Hardware name: AMD Majolica-RN/Majolica-RN, BIOS WMJ0429N_Weekly_20_04_2 04/29/2020 [ 65.920527] Call Trace: [ 65.920529] <TASK> [ 65.920532] dump_stack_lvl+0x48/0x70 [ 65.920541] dump_stack+0x10/0x20 [ 65.920543] __ubsan_handle_out_of_bounds+0xa2/0xe0 [ 65.920549] dcn21_link_encoder_create+0xd9/0x140 [amdgpu] [ 65.921009] link_create+0x6d3/0xed0 [amdgpu] [ 65.921355] create_links+0x18a/0x4e0 [amdgpu] [ 65.921679] dc_create+0x360/0x720 [amdgpu] [ 65.921999] ? dmi_matches+0xa0/0x220 [ 65.922004] amdgpu_dm_init+0x2b6/0x2c90 [amdgpu] [ 65.922342] ? console_unlock+0x77/0x120 [ 65.922348] ? dev_printk_emit+0x86/0xb0 [ 65.922354] dm_hw_init+0x15/0x40 [amdgpu] [ 65.922686] amdgpu_device_init+0x26a8/0x33a0 [amdgpu] [ 65.922921] amdgpu_driver_load_kms+0x1b/0xa0 [amdgpu] [ 65.923087] amdgpu_pci_probe+0x1b7/0x630 [amdgpu] [ 65.923087] local_pci_probe+0x4b/0xb0 [ 65.923087] pci_device_probe+0xc8/0x280 [ 65.923087] really_probe+0x187/0x300 [ 65.923087] __driver_probe_device+0x85/0x130 [ 65.923087] driver_probe_device+0x24/0x110 [ 65.923087] __driver_attach+0xac/0x1d0 [ 65.923087] ? __pfx___driver_attach+0x10/0x10 [ 65.923087] bus_for_each_dev+0x7d/0xd0 [ 65.923087] driver_attach+0x1e/0x30 [ 65.923087] bus_add_driver+0xf2/0x200 [ 65.923087] driver_register+0x64/0x130 [ 65.923087] ? __pfx_amdgpu_init+0x10/0x10 [amdgpu] [ 65.923087] __pci_register_driver+0x61/0x70 [ 65.923087] amdgpu_init+0x7d/0xff0 [amdgpu] [ 65.923087] do_one_initcall+0x49/0x310 [ 65.923087] ? kmalloc_trace+0x136/0x360 [ 65.923087] do_init_module+0x6a/0x270 [ 65.923087] load_module+0x1fce/0x23a0 [ 65.923087] init_module_from_file+0x9c/0xe0 [ 65.923087] ? init_module_from_file+0x9c/0xe0 [ 65.923087] idempotent_init_module+0x179/0x230 [ 65.923087] __x64_sys_finit_module+0x5d/0xa0 [ 65.923087] do_syscall_64+0x76/0x120 [ 65.923087] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ 65.923087] RIP: 0033:0x7f2d80f1e88d [ 65.923087] Code: 5b 41 5c c3 66 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 73 b5 0f 00 f7 d8 64 89 01 48 [ 65.923087] RSP: 002b:00007ffc7bc1aa78 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 [ 65.923087] RAX: ffffffffffffffda RBX: 0000564c9c1db130 RCX: 00007f2d80f1e88d [ 65.923087] RDX: 0000000000000000 RSI: 0000564c9c1e5480 RDI: 000000000000000f [ 65.923087] RBP: 0000000000040000 R08: 0000000000000000 R09: 0000000000000002 [ 65.923087] R10: 000000000000000f R11: 0000000000000246 R12: 0000564c9c1e5480 [ 65.923087] R13: 0000564c9c1db260 R14: 0000000000000000 R15: 0000564c9c1e54b0 [ 65.923087] </TASK> [ 65.923927] ---[ end trace ]--- Cc: Tom Chung <chiahsuan.chung@xxxxxxx> Cc: Rodrigo Siqueira <Rodrigo.Siqueira@xxxxxxx> Cc: Roman Li <roman.li@xxxxxxx> Cc: Alex Hung <alex.hung@xxxxxxx> Cc: Aurabindo Pillai <aurabindo.pillai@xxxxxxx> Cc: Harry Wentland <harry.wentland@xxxxxxx> Cc: Hamza Mahfooz <hamza.mahfooz@xxxxxxx> Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@xxxxxxx> --- drivers/gpu/drm/amd/display/dc/resource/dcn21/dcn21_resource.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/display/dc/resource/dcn21/dcn21_resource.c b/drivers/gpu/drm/amd/display/dc/resource/dcn21/dcn21_resource.c index 347e6aaea582..e0f99b95f9bc 100644 --- a/drivers/gpu/drm/amd/display/dc/resource/dcn21/dcn21_resource.c +++ b/drivers/gpu/drm/amd/display/dc/resource/dcn21/dcn21_resource.c @@ -1298,7 +1298,8 @@ static struct link_encoder *dcn21_link_encoder_create( kzalloc(sizeof(struct dcn21_link_encoder), GFP_KERNEL); int link_regs_id; - if (!enc21) + if (!enc21 || (enc_init_data->hpd_source < HPD_SOURCEID1 || + enc_init_data->hpd_source >= HPD_SOURCEID_COUNT)) return NULL; link_regs_id = -- 2.34.1
