From: Tom St Denis <tom.stdenis@xxxxxxx> commit 5bbc6604a62814511c32f2e39bc9ffb2c1b92cbe upstream. The offset into the array was specified in bytes but should be in terms of 32-bit words. Also prevent large reads that would also cause a buffer overread. v2: Read from correct offset from internal storage buffer. Signed-off-by: Tom St Denis <tom.stdenis@xxxxxxx> Acked-by: Christian König <christian.koenig@xxxxxxx> Reviewed-by: Alex Deucher <alexander.deucher@xxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c @@ -694,11 +694,11 @@ static ssize_t amdgpu_debugfs_gpr_read(s ssize_t result = 0; uint32_t offset, se, sh, cu, wave, simd, thread, bank, *data; - if (size & 3 || *pos & 3) + if (size > 4096 || size & 3 || *pos & 3) return -EINVAL; /* decode offset */ - offset = *pos & GENMASK_ULL(11, 0); + offset = (*pos & GENMASK_ULL(11, 0)) >> 2; se = (*pos & GENMASK_ULL(19, 12)) >> 12; sh = (*pos & GENMASK_ULL(27, 20)) >> 20; cu = (*pos & GENMASK_ULL(35, 28)) >> 28; @@ -729,7 +729,7 @@ static ssize_t amdgpu_debugfs_gpr_read(s while (size) { uint32_t value; - value = data[offset++]; + value = data[result >> 2]; r = put_user(value, (uint32_t *)buf); if (r) { result = r;