Integer overflows in memory allocation in Das U-Boot before 2025.01-rc1 occur for a crafted squashfs filesystem via sbrk, via request2size, or because ptrdiff_t is mishandled on x86_64.
The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.