[SRU][N][PATCH 1/1] drm/amdgpu: fix mc_data out-of-bounds read warning

[Bethany Jamison]

From: Tim Huang <Tim.Huang at amd.com>

[ Upstream commit 51dfc0a4d609fe700750a62f41447f01b8c9ea50 ]

Clear warning that read mc_data[i-1] may out-of-bounds.

Signed-off-by: Tim Huang <Tim.Huang at amd.com>
Reviewed-by: Alex Deucher <alexander.deucher at amd.com>
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
Signed-off-by: Sasha Levin <sashal at kernel.org>
(cherry picked from commit 578ae965e8b90cd09edeb0252b50fa0503ea35c5 linux-6.10.y)
CVE-2024-46722
Signed-off-by: Bethany Jamison <bethany.jamison at canonical.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c
index dce9e7d5e4ec6..a14a54a734c12 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c
@@ -1476,6 +1476,8 @@ int amdgpu_atombios_init_mc_reg_table(struct amdgpu_device *adev,
 										(u32)le32_to_cpu(*((u32 *)reg_data + j));
 									j++;
 								} else if ((reg_table->mc_reg_address[i].pre_reg_data & LOW_NIBBLE_MASK) == DATA_EQU_PREV) {
+									if (i == 0)
+										continue;
 									reg_table->mc_reg_table_entry[num_ranges].mc_data[i] =
 										reg_table->mc_reg_table_entry[num_ranges].mc_data[i - 1];
 								}
-- 
2.34.1