CVE-2020-22524 - Fix integer overflow leading to undersized allocation in PFM loader - #56
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…VE-2020-22524) Load() computed the RLE/pixel line buffer size as `const unsigned lineWidth = 3 * width;` (RGBF) or `= width;` (FLOAT), where width is an int read directly from the PFM header with no upper bound (only `width <= 0` is rejected). For the RGBF case in particular, `3 * width` is evaluated as a 32-bit signed int multiply before being stored into lineWidth, so a sufficiently large width (~715M+) silently overflows and wraps to a small value. malloc(lineWidth * sizeof(float)) then succeeds with a buffer far smaller than the real per-scanline size, while the pixel-unpacking loop right below it still iterates `for (x = 0; x < width; x++)` against the original, un-overflowed width - reading/writing past the end of that undersized lineBuffer. Compute lineWidth in size_t instead, so the multiply can't overflow before it reaches malloc(); genuinely unreasonable widths now just fail malloc() cleanly, which Load() already handles via the existing `if(!lineBuffer) throw FI_MSG_ERROR_MEMORY` check. CWE-190 (Integer Overflow) leading to CWE-787/CWE-125 (Out-of-bounds Write/Read) Fixes: CVE-2020-22524
The previous commit's edit was re-serialized as UTF-8, corrupting the file's original ISO-8859-1 "Hervé Drolon" byte sequence into a replacement character. Restore it by converting the original file to UTF-8 properly rather than accidentally.
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Load()computed the PFM line buffer size as3 * width(int/unsigned), wherewidthcomes straight from the file header with only a<= 0check — no upper bound. Past ~715M,3 * widthoverflows the 32-bit multiply and wraps small, somalloc()undersizeslineBufferwhile the unpack loop right below still iterates the original, un-overflowedwidth— reading/writing past the end of it.Computes the line width in
size_tinstead, so the multiply can't overflow before it reachesmalloc().Fixes: CVE-2020-22524