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From:   Daniil Dulov <d.dulov@aladdin.ru>
To:     Felix Kuehling <Felix.Kuehling@amd.com>
CC:     Daniil Dulov <d.dulov@aladdin.ru>,
        Alex Deucher <alexander.deucher@amd.com>,
        =?UTF-8?q?Christian=20K=C3=B6nig?= <christian.koenig@amd.com>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>, Oak Zeng <oak.zeng@intel.com>,
        <amd-gfx@lists.freedesktop.org>, <dri-devel@lists.freedesktop.org>,
        <linux-kernel@vger.kernel.org>,
        "# v5 . 3+" <stable@vger.kernel.org>,
        <lvc-project@linuxtesting.org>
Subject: [PATCH v2] drm/amdkfd: Fix potential deallocation of previously deallocated memory.
Date:   Thu, 11 May 2023 04:23:14 -0700
Message-ID: <20230511112314.29322-1-d.dulov@aladdin.ru>
In-Reply-To: <ZD7W5aaslOXLg707@ashyti-mobl2.lan>
References: 
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Precedence: bulk

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@aladdin.ru>
---
v2: Move if (retval) inside previous if as Andi Shyti <andi.shyti@linux.intel.com> 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