tif_thunder: avoid unsigned integer overflow (not a bug). Fixes https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=16632

This commit is contained in:
Even Rouault 2019-08-23 12:28:25 +02:00
parent f277541bd8
commit c9edebfdb0
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@ -122,17 +122,17 @@ ThunderDecode(TIFF* tif, uint8* op, tmsize_t maxpixels)
break;
case THUNDER_2BITDELTAS: /* 2-bit deltas */
if ((delta = ((n >> 4) & 3)) != DELTA2_SKIP)
SETPIXEL(op, lastpixel + twobitdeltas[delta]);
SETPIXEL(op, (unsigned)((int)lastpixel + twobitdeltas[delta]));
if ((delta = ((n >> 2) & 3)) != DELTA2_SKIP)
SETPIXEL(op, lastpixel + twobitdeltas[delta]);
SETPIXEL(op, (unsigned)((int)lastpixel + twobitdeltas[delta]));
if ((delta = (n & 3)) != DELTA2_SKIP)
SETPIXEL(op, lastpixel + twobitdeltas[delta]);
SETPIXEL(op, (unsigned)((int)lastpixel + twobitdeltas[delta]));
break;
case THUNDER_3BITDELTAS: /* 3-bit deltas */
if ((delta = ((n >> 3) & 7)) != DELTA3_SKIP)
SETPIXEL(op, lastpixel + threebitdeltas[delta]);
SETPIXEL(op, (unsigned)((int)lastpixel + threebitdeltas[delta]));
if ((delta = (n & 7)) != DELTA3_SKIP)
SETPIXEL(op, lastpixel + threebitdeltas[delta]);
SETPIXEL(op, (unsigned)((int)lastpixel + threebitdeltas[delta]));
break;
case THUNDER_RAW: /* raw data */
SETPIXEL(op, n);