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