Hello John Stultz,
The patch 7b87ea704fd9: "dma-buf: heaps: Add heap helpers" from Oct
21, 2019, leads to the following static checker warning:
drivers/dma-buf/heaps/heap-helpers.c:165 dma_heap_vm_fault()
warn: uncapped user index 'buffer->pages[vmf->pgoff]'
drivers/dma-buf/heaps/heap-helpers.c
160 static vm_fault_t dma_heap_vm_fault(struct vm_fault *vmf)
161 {
162 struct vm_area_struct *vma = vmf->vma;
163 struct heap_helper_buffer *buffer = vma->vm_private_data;
164
165 vmf->page = buffer->pages[vmf->pgoff];
^^^^^^^^^^
Smatch for some reason thinks this needs to be checked. Smatch also
gets confused by these fault handlers and thinks there is some recursion
involved...
166 get_page(vmf->page);
167
168 return 0;
169 }
170
171 static const struct vm_operations_struct dma_heap_vm_ops = {
172 .fault = dma_heap_vm_fault,
173 };
174
regards,
dan carpenter
