Similar to the handling of amdgpu_sa_bo_next_hole in commit 6a15f3ff19a8
("drm/amdgpu: Initialize fences array entries in amdgpu_sa_bo_next_hole"),
we thought a patch might be needed here as well.
The entries were only initialized once in radeon_sa_bo_new. If a fence
wasn't signalled yet in the first radeon_sa_bo_next_hole call, but then
got signalled before a later radeon_sa_bo_next_hole call, it could
destroy the fence but leave its pointer in the array, resulting in
use-after-free in radeon_sa_bo_new.
Signed-off-by: Xiaohui Zhang <[email protected]>
---
drivers/gpu/drm/radeon/radeon_sa.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/radeon/radeon_sa.c b/drivers/gpu/drm/radeon/radeon_sa.c
index 310c322c7112..0981948bd9ed 100644
--- a/drivers/gpu/drm/radeon/radeon_sa.c
+++ b/drivers/gpu/drm/radeon/radeon_sa.c
@@ -267,6 +267,8 @@ static bool radeon_sa_bo_next_hole(struct radeon_sa_manager *sa_manager,
for (i = 0; i < RADEON_NUM_RINGS; ++i) {
struct radeon_sa_bo *sa_bo;
+ fences[i] = NULL;
+
if (list_empty(&sa_manager->flist[i])) {
continue;
}
@@ -332,10 +334,8 @@ int radeon_sa_bo_new(struct radeon_device *rdev,
spin_lock(&sa_manager->wq.lock);
do {
- for (i = 0; i < RADEON_NUM_RINGS; ++i) {
- fences[i] = NULL;
+ for (i = 0; i < RADEON_NUM_RINGS; ++i)
tries[i] = 0;
- }
do {
radeon_sa_bo_try_free(sa_manager);
--
2.17.1
Applied. Thanks!
Alex
On Tue, Jun 7, 2022 at 12:04 PM Xiaohui Zhang <[email protected]> wrote:
>
> Similar to the handling of amdgpu_sa_bo_next_hole in commit 6a15f3ff19a8
> ("drm/amdgpu: Initialize fences array entries in amdgpu_sa_bo_next_hole"),
> we thought a patch might be needed here as well.
>
> The entries were only initialized once in radeon_sa_bo_new. If a fence
> wasn't signalled yet in the first radeon_sa_bo_next_hole call, but then
> got signalled before a later radeon_sa_bo_next_hole call, it could
> destroy the fence but leave its pointer in the array, resulting in
> use-after-free in radeon_sa_bo_new.
>
> Signed-off-by: Xiaohui Zhang <[email protected]>
> ---
> drivers/gpu/drm/radeon/radeon_sa.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/radeon_sa.c b/drivers/gpu/drm/radeon/radeon_sa.c
> index 310c322c7112..0981948bd9ed 100644
> --- a/drivers/gpu/drm/radeon/radeon_sa.c
> +++ b/drivers/gpu/drm/radeon/radeon_sa.c
> @@ -267,6 +267,8 @@ static bool radeon_sa_bo_next_hole(struct radeon_sa_manager *sa_manager,
> for (i = 0; i < RADEON_NUM_RINGS; ++i) {
> struct radeon_sa_bo *sa_bo;
>
> + fences[i] = NULL;
> +
> if (list_empty(&sa_manager->flist[i])) {
> continue;
> }
> @@ -332,10 +334,8 @@ int radeon_sa_bo_new(struct radeon_device *rdev,
>
> spin_lock(&sa_manager->wq.lock);
> do {
> - for (i = 0; i < RADEON_NUM_RINGS; ++i) {
> - fences[i] = NULL;
> + for (i = 0; i < RADEON_NUM_RINGS; ++i)
> tries[i] = 0;
> - }
>
> do {
> radeon_sa_bo_try_free(sa_manager);
> --
> 2.17.1
>
Am 07.06.22 um 17:19 schrieb Xiaohui Zhang:
> Similar to the handling of amdgpu_sa_bo_next_hole in commit 6a15f3ff19a8
> ("drm/amdgpu: Initialize fences array entries in amdgpu_sa_bo_next_hole"),
> we thought a patch might be needed here as well.
>
> The entries were only initialized once in radeon_sa_bo_new. If a fence
> wasn't signalled yet in the first radeon_sa_bo_next_hole call, but then
> got signalled before a later radeon_sa_bo_next_hole call, it could
> destroy the fence but leave its pointer in the array, resulting in
> use-after-free in radeon_sa_bo_new.
I would rather like to see the sub allocator moved into a common drm helper.
Regards,
Christian.
>
> Signed-off-by: Xiaohui Zhang <[email protected]>
> ---
> drivers/gpu/drm/radeon/radeon_sa.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/radeon_sa.c b/drivers/gpu/drm/radeon/radeon_sa.c
> index 310c322c7112..0981948bd9ed 100644
> --- a/drivers/gpu/drm/radeon/radeon_sa.c
> +++ b/drivers/gpu/drm/radeon/radeon_sa.c
> @@ -267,6 +267,8 @@ static bool radeon_sa_bo_next_hole(struct radeon_sa_manager *sa_manager,
> for (i = 0; i < RADEON_NUM_RINGS; ++i) {
> struct radeon_sa_bo *sa_bo;
>
> + fences[i] = NULL;
> +
> if (list_empty(&sa_manager->flist[i])) {
> continue;
> }
> @@ -332,10 +334,8 @@ int radeon_sa_bo_new(struct radeon_device *rdev,
>
> spin_lock(&sa_manager->wq.lock);
> do {
> - for (i = 0; i < RADEON_NUM_RINGS; ++i) {
> - fences[i] = NULL;
> + for (i = 0; i < RADEON_NUM_RINGS; ++i)
> tries[i] = 0;
> - }
>
> do {
> radeon_sa_bo_try_free(sa_manager);