[PATCH v2] drm/amdkfd: Fix potential deallocation of previously deallocated memory.

From: Daniil Dulov
Date: Thu May 11 2023 - 07:27:50 EST


Pointer mqd_mem_obj can be deallocated in kfd_gtt_sa_allocate().
The function then returns non-zero value, which causes the second deallocation.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: d1f8f0d17d40 ("drm/amdkfd: Move non-sdma mqd allocation out of init_mqd")
Signed-off-by: Daniil Dulov <d.dulov@xxxxxxxxxx>
---
v2: Move if (retval) inside previous if as Andi Shyti <andi.shyti@xxxxxxxxxxxxxxx> suggested.
drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_v9.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_v9.c b/drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_v9.c
index 3b6f5963180d..dadeb2013fd9 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_v9.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_v9.c
@@ -113,18 +113,19 @@ static struct kfd_mem_obj *allocate_mqd(struct kfd_dev *kfd,
&(mqd_mem_obj->gtt_mem),
&(mqd_mem_obj->gpu_addr),
(void *)&(mqd_mem_obj->cpu_ptr), true);
+
+ if (retval) {
+ kfree(mqd_mem_obj);
+ return NULL;
+ }
} else {
retval = kfd_gtt_sa_allocate(kfd, sizeof(struct v9_mqd),
&mqd_mem_obj);
- }
-
- if (retval) {
- kfree(mqd_mem_obj);
- return NULL;
+ if (retval)
+ return NULL;
}

return mqd_mem_obj;
-
}

static void init_mqd(struct mqd_manager *mm, void **mqd,
--
2.25.1