61ff560 relocator: Protect grub_relocator_alloc_chunk_align() max_addr against integer underflow

13 files Authored by Alexey Makhalov 3 years ago, Committed by Daniel Kiper 3 years ago,
    relocator: Protect grub_relocator_alloc_chunk_align() max_addr against integer underflow
    
    This commit introduces integer underflow mitigation in max_addr calculation
    in grub_relocator_alloc_chunk_align() invocation.
    
    It consists of 2 fixes:
      1. Introduced grub_relocator_alloc_chunk_align_safe() wrapper function to perform
         sanity check for min/max and size values, and to make safe invocation of
         grub_relocator_alloc_chunk_align() with validated max_addr value. Replace all
         invocations such as grub_relocator_alloc_chunk_align(..., min_addr, max_addr - size, size, ...)
         by grub_relocator_alloc_chunk_align_safe(..., min_addr, max_addr, size, ...).
      2. Introduced UP_TO_TOP32(s) macro for the cases where max_addr is 32-bit top
         address (0xffffffff - size + 1) or similar.
    
    Signed-off-by: Alexey Makhalov <amakhalov@vmware.com>
    Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
    
        
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