Re: [PATCH] Fix IB va_start+ib_bytes range check on 32Bit systems
From: Christian KÃnig
Date: Thu Mar 30 2017 - 04:36:43 EST
Am 30.03.2017 um 03:41 schrieb Michel DÃnzer:
On 30/03/17 12:18 AM, Christian KÃnig wrote:
Am 29.03.2017 um 16:54 schrieb Michel DÃnzer:
On 29/03/17 10:22 PM, Christian KÃnig wrote:
Am 29.03.2017 um 11:18 schrieb Jan Burgmeier:
Signed-off-by: Jan Burgmeier <jan.burgmeier@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
index 99424cb8020b..583d22974e14 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
@@ -908,6 +908,7 @@ static int amdgpu_cs_ib_fill(struct amdgpu_device
*adev,
struct amdgpu_bo *aobj = NULL;
uint64_t offset;
uint8_t *kptr;
+ uint64_t it_last;
m = amdgpu_cs_find_mapping(parser, chunk_ib->va_start,
&aobj);
@@ -916,8 +917,9 @@ static int amdgpu_cs_ib_fill(struct amdgpu_device
*adev,
return -EINVAL;
}
+ it_last = m->it.last;
if ((chunk_ib->va_start + chunk_ib->ib_bytes) >
- (m->it.last + 1) * AMDGPU_GPU_PAGE_SIZE) {
+ (it_last + 1) * AMDGPU_GPU_PAGE_SIZE) {
Nice catch, but just adding a u64 case should do here as well. E.g:
if ((chunk_ib->va_start + chunk_ib->ib_bytes) >
(u64)(m->it.last + 1) * AMDGPU_GPU_PAGE_SIZE) {
That won't work correctly if m->it.last == 0xffffffff ? Or is that not
possible?
Hui, why? is it.last signed?
No. If m->it.last == 0xffffffff, (m->it.last + 1) == 0, the u64 cast
won't change that. I thought that would be bad, but maybe not?
Ah, good catch. Yes the u64 cast needs to be inside the (), not outside.
Christian.