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From:   Chia-I Wu <olvaffe@gmail.com>
To:     dri-devel@lists.freedesktop.org
Cc:     Alex Deucher <alexander.deucher@amd.com>,
        =?UTF-8?q?Christian=20K=C3=B6nig?= <christian.koenig@amd.com>,
        "Pan, Xinhui" <Xinhui.Pan@amd.com>,
        David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        Felix Kuehling <Felix.Kuehling@amd.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        =?UTF-8?q?Marek=20Ol=C5=A1=C3=A1k?= <marek.olsak@amd.com>,
        Kefeng Wang <wangkefeng.wang@huawei.com>,
        Yang Li <yang.lee@linux.alibaba.com>,
        Suren Baghdasaryan <surenb@google.com>,
        Philip Yang <Philip.Yang@amd.com>,
        Luben Tuikov <luben.tuikov@amd.com>,
        Danijel Slivka <danijel.slivka@amd.com>,
        Mukul Joshi <mukul.joshi@amd.com>,
        Jammy Zhou <Jammy.Zhou@amd.com>, amd-gfx@lists.freedesktop.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH 2/2] amdgpu: validate drm_amdgpu_gem_va against overflows
Date:   Tue,  9 May 2023 11:32:55 -0700
Message-ID: <20230509183301.1745462-2-olvaffe@gmail.com>
In-Reply-To: <20230509183301.1745462-1-olvaffe@gmail.com>
References: <20230509183301.1745462-1-olvaffe@gmail.com>
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The existing validations are incorrect and insufficient.  This is
motivated by OOB access in amdgpu_vm_update_range when
offset_in_bo+map_size overflows.

Fixes: 9f7eb5367d00 ("drm/amdgpu: actually use the VM map parameters")
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 7 +++++--
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c  | 6 ++----
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
index 071f6565cf971..36d5adfdf0f69 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
@@ -688,8 +688,11 @@ int amdgpu_gem_va_ioctl(struct drm_device *dev, void *data,
 		return -EINVAL;
 	}
 
-	if (args->map_size == 0) {
-		dev_dbg(dev->dev, "invalid map_size 0x%LX\n", args->map_size);
+	if (args->map_size == 0 ||
+	    args->va_address + args->map_size < args->va_address ||
+	    args->offset_in_bo + args->map_size < args->offset_in_bo) {
+		dev_dbg(dev->dev, "invalid map_size 0x%LX (va_address 0x%LX, offset_in_bo 0x%LX)\n",
+			args->map_size, args->va_address, args->offset_in_bo);
 		return -EINVAL;
 	}
 
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index fa5819d581655..cd0a0f06e11ef 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -1437,8 +1437,7 @@ int amdgpu_vm_bo_map(struct amdgpu_device *adev,
 
 	/* make sure object fit at this offset */
 	eaddr = saddr + size - 1;
-	if (saddr >= eaddr ||
-	    (bo && offset + size > amdgpu_bo_size(bo)) ||
+	if ((bo && offset + size > amdgpu_bo_size(bo)) ||
 	    (eaddr >= adev->vm_manager.max_pfn << AMDGPU_GPU_PAGE_SHIFT))
 		return -EINVAL;
 
@@ -1498,8 +1497,7 @@ int amdgpu_vm_bo_replace_map(struct amdgpu_device *adev,
 
 	/* make sure object fit at this offset */
 	eaddr = saddr + size - 1;
-	if (saddr >= eaddr ||
-	    (bo && offset + size > amdgpu_bo_size(bo)) ||
+	if ((bo && offset + size > amdgpu_bo_size(bo)) ||
 	    (eaddr >= adev->vm_manager.max_pfn << AMDGPU_GPU_PAGE_SHIFT))
 		return -EINVAL;
 
-- 
2.40.1.521.gf1e218fcd8-goog