diff options
| author | Candice Li <candice.li@amd.com> | 2026-05-13 12:31:57 +0800 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2026-05-19 11:52:03 -0400 |
| commit | a99cd231cd924b7160fecb9fb3a94b801522323b (patch) | |
| tree | 0079024ff493c7dbed6773aa9c1688c435bfa67e | |
| parent | 27ef1795bc4e47cae838e0a3ced531c549f9b23d (diff) | |
drm/amdgpu: Bound GPIO I2C table entry count from VBIOS
Reject undersized tables and cap the derived entry count
to AMDGPU_MAX_I2C_BUS so we do not overrun adev->i2c_bus[]
or walk an absurd number of entries on corrupt size fields.
Signed-off-by: Candice Li <candice.li@amd.com>
Reviewed-by: Tao Zhou <tao.zhou1@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
| -rw-r--r-- | drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c | 24 |
1 files changed, 18 insertions, 6 deletions
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c index 3698dd0330ff..acd22bff1882 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c @@ -36,6 +36,21 @@ #include "atombios_encoders.h" #include "bif/bif_4_1_d.h" +/* VBIOS-reported table size is unchecked against the image; cap iterations and + * adev->i2c_bus[] indexing to AMDGPU_MAX_I2C_BUS. + */ +static int amdgpu_atombios_gpio_i2c_num_entries(uint16_t size) +{ + u32 bytes; + + if (size < sizeof(ATOM_COMMON_TABLE_HEADER)) + return 0; + + bytes = size - sizeof(ATOM_COMMON_TABLE_HEADER); + return (int)min_t(u32, bytes / sizeof(ATOM_GPIO_I2C_ASSIGMENT), + AMDGPU_MAX_I2C_BUS); +} + static struct amdgpu_i2c_bus_rec amdgpu_atombios_get_bus_rec_for_i2c_gpio(ATOM_GPIO_I2C_ASSIGMENT *gpio) { struct amdgpu_i2c_bus_rec i2c; @@ -96,8 +111,7 @@ struct amdgpu_i2c_bus_rec amdgpu_atombios_lookup_i2c_gpio(struct amdgpu_device * if (amdgpu_atom_parse_data_header(ctx, index, &size, NULL, NULL, &data_offset)) { i2c_info = (struct _ATOM_GPIO_I2C_INFO *)(ctx->bios + data_offset); - num_indices = (size - sizeof(ATOM_COMMON_TABLE_HEADER)) / - sizeof(ATOM_GPIO_I2C_ASSIGMENT); + num_indices = amdgpu_atombios_gpio_i2c_num_entries(size); gpio = &i2c_info->asGPIO_Info[0]; for (i = 0; i < num_indices; i++) { @@ -127,8 +141,7 @@ void amdgpu_atombios_i2c_init(struct amdgpu_device *adev) if (amdgpu_atom_parse_data_header(ctx, index, &size, NULL, NULL, &data_offset)) { i2c_info = (struct _ATOM_GPIO_I2C_INFO *)(ctx->bios + data_offset); - num_indices = (size - sizeof(ATOM_COMMON_TABLE_HEADER)) / - sizeof(ATOM_GPIO_I2C_ASSIGMENT); + num_indices = amdgpu_atombios_gpio_i2c_num_entries(size); gpio = &i2c_info->asGPIO_Info[0]; for (i = 0; i < num_indices; i++) { @@ -158,8 +171,7 @@ void amdgpu_atombios_oem_i2c_init(struct amdgpu_device *adev, u8 i2c_id) if (amdgpu_atom_parse_data_header(ctx, index, &size, NULL, NULL, &data_offset)) { i2c_info = (struct _ATOM_GPIO_I2C_INFO *)(ctx->bios + data_offset); - num_indices = (size - sizeof(ATOM_COMMON_TABLE_HEADER)) / - sizeof(ATOM_GPIO_I2C_ASSIGMENT); + num_indices = amdgpu_atombios_gpio_i2c_num_entries(size); gpio = &i2c_info->asGPIO_Info[0]; for (i = 0; i < num_indices; i++) { |