[PATCH v3] drm/amd/display: Fix out-of-bounds access in 'dcn21_link_encoder_create'

Thu Sep 26 14:08:55 UTC 2024

[Public]

Reviewed-by: Roman Li <roman.li at amd.com>

> -----Original Message-----
> From: SHANMUGAM, SRINIVASAN <SRINIVASAN.SHANMUGAM at amd.com>
> Sent: Wednesday, September 25, 2024 11:10 AM
> To: Siqueira, Rodrigo <Rodrigo.Siqueira at amd.com>; Pillai, Aurabindo
> <Aurabindo.Pillai at amd.com>
> Cc: amd-gfx at lists.freedesktop.org; SHANMUGAM, SRINIVASAN
> <SRINIVASAN.SHANMUGAM at amd.com>; Chung, ChiaHsuan (Tom)
> <ChiaHsuan.Chung at amd.com>; Li, Roman <Roman.Li at amd.com>; Hung, Alex
> <Alex.Hung at amd.com>; Wentland, Harry <Harry.Wentland at amd.com>; Mahfooz,
> Hamza <Hamza.Mahfooz at amd.com>
> Subject: [PATCH v3] drm/amd/display: Fix out-of-bounds access in
> 'dcn21_link_encoder_create'
>
> 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.
>
> 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 at amd.com>
> Cc: Rodrigo Siqueira <Rodrigo.Siqueira at amd.com>
> Cc: Roman Li <roman.li at amd.com>
> Cc: Alex Hung <alex.hung at amd.com>
> Cc: Aurabindo Pillai <aurabindo.pillai at amd.com>
> Cc: Harry Wentland <harry.wentland at amd.com>
> Cc: Hamza Mahfooz <hamza.mahfooz at amd.com>
> Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam at amd.com>
> ---
> v2:
>  - Changed to ARRAY_SIZE() to be generic (Roman)
>
> v3:
>  - Updated git commit message
>
>  drivers/gpu/drm/amd/display/dc/resource/dcn21/dcn21_resource.c | 2 +-
>  1 file changed, 1 insertion(+), 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..14b28841657d 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 +1298,7 @@ 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 >=
> +ARRAY_SIZE(link_enc_hpd_regs))
>               return NULL;
>
>       link_regs_id =
> --
> 2.34.1