gpu: nvgpu: avoid possible ovrflw in dmabuf check

In gk20a_vm_map_buffer, when checking dmabuf size, avoid possible
overflow of buffer offset + buffer size

Bug 1793926

Change-Id: Iaa85bbd2942546015a233f34388309c6ba01412c
Signed-off-by: Peter Daifuku <pdaifuku@nvidia.com>
Reviewed-on: http://git-master/r/1488051
(cherry picked from commit 62346ede6c0863d36dc5d91527647130a13eff53)
Reviewed-on: http://git-master/r/1501696
(cherry picked from commit 745c273ac80fad14f019b7c59bb797c4e22f4781)
Reviewed-on: https://git-master.nvidia.com/r/1528182
Reviewed-by: Automatic_Commit_Validation_User
GVS: Gerrit_Virtual_Submit
Reviewed-by: Alex Waterman <alexw@nvidia.com>
Reviewed-by: Vladislav Buzov <vbuzov@nvidia.com>
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
This commit is contained in:
Peter Daifuku
2017-05-23 10:32:33 -07:00
committed by mobile promotions
parent f391f53c08
commit 02acac71b3

View File

@@ -1997,7 +1997,15 @@ int nvgpu_vm_map_buffer(struct vm_gk20a *vm,
return PTR_ERR(dmabuf); return PTR_ERR(dmabuf);
} }
if (dmabuf->size < (buffer_offset + mapping_size)) { /* verify that we're not overflowing the buffer, i.e.
* (buffer_offset + mapping_size)> dmabuf->size.
*
* Since buffer_offset + mapping_size could overflow, first check
* that mapping size < dmabuf_size, at which point we can subtract
* mapping_size from both sides for the final comparison.
*/
if ((mapping_size > dmabuf->size) ||
(buffer_offset > (dmabuf->size - mapping_size))) {
nvgpu_err(gk20a_from_vm(vm), nvgpu_err(gk20a_from_vm(vm),
"buf size %llx < (offset(%llx) + map_size(%llx))\n", "buf size %llx < (offset(%llx) + map_size(%llx))\n",
(u64)dmabuf->size, buffer_offset, mapping_size); (u64)dmabuf->size, buffer_offset, mapping_size);