From: Srinivasan Shanmugam srinivasan.shanmugam@amd.com

commit cdb637d339572398821204a1142d8d615668f1e9 upstream.

The issue arises when the array 'adev->vcn.vcn_config' is accessed before checking if the index 'adev->vcn.num_vcn_inst' is within the bounds of the array.

The fix involves moving the bounds check before the array access. This ensures that 'adev->vcn.num_vcn_inst' is within the bounds of the array before it is used as an index.

Fixes the below: drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c:1289 amdgpu_discovery_reg_base_init() error: testing array offset 'adev->vcn.num_vcn_inst' after use.

Fixes: a0ccc717c4ab ("drm/amdgpu/discovery: validate VCN and SDMA instances") Cc: Christian König christian.koenig@amd.com Cc: Alex Deucher alexander.deucher@amd.com Signed-off-by: Srinivasan Shanmugam srinivasan.shanmugam@amd.com Reviewed-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com [ kovalev: bp to fix CVE-2024-27042 ] Signed-off-by: Vasiliy Kovalev kovalev@altlinux.org --- drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c index d8441e273..8bc3a4bf3 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c @@ -1128,15 +1128,16 @@ static int amdgpu_discovery_reg_base_init(struct amdgpu_device *adev) * 0b10 : encode is disabled * 0b01 : decode is disabled */ - adev->vcn.vcn_config[adev->vcn.num_vcn_inst] = - ip->revision & 0xc0; - ip->revision &= ~0xc0; - if (adev->vcn.num_vcn_inst < AMDGPU_MAX_VCN_INSTANCES) + if (adev->vcn.num_vcn_inst < AMDGPU_MAX_VCN_INSTANCES) { + adev->vcn.vcn_config[adev->vcn.num_vcn_inst] = + ip->revision & 0xc0; adev->vcn.num_vcn_inst++; + } else dev_err(adev->dev, "Too many VCN instances: %d vs %d\n", adev->vcn.num_vcn_inst + 1, AMDGPU_MAX_VCN_INSTANCES); + ip->revision &= ~0xc0; } if (le16_to_cpu(ip->hw_id) == SDMA0_HWID || le16_to_cpu(ip->hw_id) == SDMA1_HWID ||