mget(struct magic_set *ms, const unsigned char *s, struct magic *m,
    size_t nbytes, size_t o, unsigned int cont_level, int mode, int text,
    int flip, int recursion_level, int *printed_something,
    int *need_separator, int *returnval)
{
	uint32_t soffset, offset = ms->offset;
	uint32_t lhs;
	int rv, oneed_separator, in_type;
	char *sbuf, *rbuf;
	union VALUETYPE *p = &ms->ms_value;
	struct mlist ml;

	if (recursion_level >= 20) {
		file_error(ms, 0, "recursion nesting exceeded");
		return -1;
	}

	if (mcopy(ms, p, m->type, m->flag & INDIR, s, (uint32_t)(offset + o),
	    (uint32_t)nbytes, m) == -1)
		return -1;

	if ((ms->flags & MAGIC_DEBUG) != 0) {
		fprintf(stderr, "mget(type=%d, flag=%x, offset=%u, o=%"
		    SIZE_T_FORMAT "u, " "nbytes=%" SIZE_T_FORMAT "u)\n",
		    m->type, m->flag, offset, o, nbytes);
		mdebug(offset, (char *)(void *)p, sizeof(union VALUETYPE));
#ifndef COMPILE_ONLY
		file_mdump(m);
#endif
	}

	if (m->flag & INDIR) {
		int off = m->in_offset;
		if (m->in_op & FILE_OPINDIRECT) {
			const union VALUETYPE *q = CAST(const union VALUETYPE *,
			    ((const void *)(s + offset + off)));
			switch (cvt_flip(m->in_type, flip)) {
			case FILE_BYTE:
				off = q->b;
				break;
			case FILE_SHORT:
				off = q->h;
				break;
			case FILE_BESHORT:
				off = (short)((q->hs[0]<<8)|(q->hs[1]));
				break;
			case FILE_LESHORT:
				off = (short)((q->hs[1]<<8)|(q->hs[0]));
				break;
			case FILE_LONG:
				off = q->l;
				break;
			case FILE_BELONG:
			case FILE_BEID3:
				off = (int32_t)((q->hl[0]<<24)|(q->hl[1]<<16)|
						 (q->hl[2]<<8)|(q->hl[3]));
				break;
			case FILE_LEID3:
			case FILE_LELONG:
				off = (int32_t)((q->hl[3]<<24)|(q->hl[2]<<16)|
						 (q->hl[1]<<8)|(q->hl[0]));
				break;
			case FILE_MELONG:
				off = (int32_t)((q->hl[1]<<24)|(q->hl[0]<<16)|
						 (q->hl[3]<<8)|(q->hl[2]));
				break;
			}
			if ((ms->flags & MAGIC_DEBUG) != 0)
				fprintf(stderr, "indirect offs=%u\n", off);
		}
		switch (in_type = cvt_flip(m->in_type, flip)) {
		case FILE_BYTE:
			if (OFFSET_OOB(nbytes, offset, 1))
				return 0;
			if (off) {
				switch (m->in_op & FILE_OPS_MASK) {
				case FILE_OPAND:
					offset = p->b & off;
					break;
				case FILE_OPOR:
					offset = p->b | off;
					break;
				case FILE_OPXOR:
					offset = p->b ^ off;
					break;
				case FILE_OPADD:
					offset = p->b + off;
					break;
				case FILE_OPMINUS:
					offset = p->b - off;
					break;
				case FILE_OPMULTIPLY:
					offset = p->b * off;
					break;
				case FILE_OPDIVIDE:
					offset = p->b / off;
					break;
				case FILE_OPMODULO:
					offset = p->b % off;
					break;
				}
			} else
				offset = p->b;
			if (m->in_op & FILE_OPINVERSE)
				offset = ~offset;
			break;
		case FILE_BESHORT:
			if (OFFSET_OOB(nbytes, offset, 2))
				return 0;
			lhs = (p->hs[0] << 8) | p->hs[1];
			if (off) {
				switch (m->in_op & FILE_OPS_MASK) {
				case FILE_OPAND:
					offset = lhs & off;
					break;
				case FILE_OPOR:
					offset = lhs | off;
					break;
				case FILE_OPXOR:
					offset = lhs ^ off;
					break;
				case FILE_OPADD:
					offset = lhs + off;
					break;
				case FILE_OPMINUS:
					offset = lhs - off;
					break;
				case FILE_OPMULTIPLY:
					offset = lhs * off;
					break;
				case FILE_OPDIVIDE:
					offset = lhs / off;
					break;
				case FILE_OPMODULO:
					offset = lhs % off;
					break;
				}
			} else
				offset = lhs;
			if (m->in_op & FILE_OPINVERSE)
				offset = ~offset;
			break;
		case FILE_LESHORT:
			if (OFFSET_OOB(nbytes, offset, 2))
				return 0;
			lhs = (p->hs[1] << 8) | p->hs[0];
			if (off) {
				switch (m->in_op & FILE_OPS_MASK) {
				case FILE_OPAND:
					offset = lhs & off;
					break;
				case FILE_OPOR:
					offset = lhs | off;
					break;
				case FILE_OPXOR:
					offset = lhs ^ off;
					break;
				case FILE_OPADD:
					offset = lhs + off;
					break;
				case FILE_OPMINUS:
					offset = lhs - off;
					break;
				case FILE_OPMULTIPLY:
					offset = lhs * off;
					break;
				case FILE_OPDIVIDE:
					offset = lhs / off;
					break;
				case FILE_OPMODULO:
					offset = lhs % off;
					break;
				}
			} else
				offset = lhs;
			if (m->in_op & FILE_OPINVERSE)
				offset = ~offset;
			break;
		case FILE_SHORT:
			if (OFFSET_OOB(nbytes, offset, 2))
				return 0;
			if (off) {
				switch (m->in_op & FILE_OPS_MASK) {
				case FILE_OPAND:
					offset = p->h & off;
					break;
				case FILE_OPOR:
					offset = p->h | off;
					break;
				case FILE_OPXOR:
					offset = p->h ^ off;
					break;
				case FILE_OPADD:
					offset = p->h + off;
					break;
				case FILE_OPMINUS:
					offset = p->h - off;
					break;
				case FILE_OPMULTIPLY:
					offset = p->h * off;
					break;
				case FILE_OPDIVIDE:
					offset = p->h / off;
					break;
				case FILE_OPMODULO:
					offset = p->h % off;
					break;
				}
			}
			else
				offset = p->h;
			if (m->in_op & FILE_OPINVERSE)
				offset = ~offset;
			break;
		case FILE_BELONG:
		case FILE_BEID3:
			if (OFFSET_OOB(nbytes, offset, 4))
				return 0;
			lhs = (p->hl[0] << 24) | (p->hl[1] << 16) |
			    (p->hl[2] << 8) | p->hl[3];
			if (off) {
				switch (m->in_op & FILE_OPS_MASK) {
				case FILE_OPAND:
					offset = lhs & off;
					break;
				case FILE_OPOR:
					offset = lhs | off;
					break;
				case FILE_OPXOR:
					offset = lhs ^ off;
					break;
				case FILE_OPADD:
					offset = lhs + off;
					break;
				case FILE_OPMINUS:
					offset = lhs - off;
					break;
				case FILE_OPMULTIPLY:
					offset = lhs * off;
					break;
				case FILE_OPDIVIDE:
					offset = lhs / off;
					break;
				case FILE_OPMODULO:
					offset = lhs % off;
					break;
				}
			} else
				offset = lhs;
			if (m->in_op & FILE_OPINVERSE)
				offset = ~offset;
			break;
		case FILE_LELONG:
		case FILE_LEID3:
			if (OFFSET_OOB(nbytes, offset, 4))
				return 0;
			lhs = (p->hl[3] << 24) | (p->hl[2] << 16) |
			    (p->hl[1] << 8) | p->hl[0];
			if (off) {
				switch (m->in_op & FILE_OPS_MASK) {
				case FILE_OPAND:
					offset = lhs & off;
					break;
				case FILE_OPOR:
					offset = lhs | off;
					break;
				case FILE_OPXOR:
					offset = lhs ^ off;
					break;
				case FILE_OPADD:
					offset = lhs + off;
					break;
				case FILE_OPMINUS:
					offset = lhs - off;
					break;
				case FILE_OPMULTIPLY:
					offset = lhs * off;
					break;
				case FILE_OPDIVIDE:
					offset = lhs / off;
					break;
				case FILE_OPMODULO:
					offset = lhs % off;
					break;
				}
			} else
				offset = lhs;
			if (m->in_op & FILE_OPINVERSE)
				offset = ~offset;
			break;
		case FILE_MELONG:
			if (OFFSET_OOB(nbytes, offset, 4))
				return 0;
			lhs = (p->hl[1] << 24) | (p->hl[0] << 16) |
			    (p->hl[3] << 8) | p->hl[2];
			if (off) {
				switch (m->in_op & FILE_OPS_MASK) {
				case FILE_OPAND:
					offset = lhs & off;
					break;
				case FILE_OPOR:
					offset = lhs | off;
					break;
				case FILE_OPXOR:
					offset = lhs ^ off;
					break;
				case FILE_OPADD:
					offset = lhs + off;
					break;
				case FILE_OPMINUS:
					offset = lhs - off;
					break;
				case FILE_OPMULTIPLY:
					offset = lhs * off;
					break;
				case FILE_OPDIVIDE:
					offset = lhs / off;
					break;
				case FILE_OPMODULO:
					offset = lhs % off;
					break;
				}
			} else
				offset = lhs;
			if (m->in_op & FILE_OPINVERSE)
				offset = ~offset;
			break;
		case FILE_LONG:
			if (OFFSET_OOB(nbytes, offset, 4))
				return 0;
			if (off) {
				switch (m->in_op & FILE_OPS_MASK) {
				case FILE_OPAND:
					offset = p->l & off;
					break;
				case FILE_OPOR:
					offset = p->l | off;
					break;
				case FILE_OPXOR:
					offset = p->l ^ off;
					break;
				case FILE_OPADD:
					offset = p->l + off;
					break;
				case FILE_OPMINUS:
					offset = p->l - off;
					break;
				case FILE_OPMULTIPLY:
					offset = p->l * off;
					break;
				case FILE_OPDIVIDE:
					offset = p->l / off;
					break;
				case FILE_OPMODULO:
					offset = p->l % off;
					break;
				}
			} else
				offset = p->l;
			if (m->in_op & FILE_OPINVERSE)
				offset = ~offset;
			break;
		default:
			break;
		}

		switch (in_type) {
		case FILE_LEID3:
		case FILE_BEID3:
			offset = ((((offset >>  0) & 0x7f) <<  0) |
				 (((offset >>  8) & 0x7f) <<  7) |
				 (((offset >> 16) & 0x7f) << 14) |
				 (((offset >> 24) & 0x7f) << 21)) + 10;
			break;
		default:
			break;
		}

		if (m->flag & INDIROFFADD) {
			offset += ms->c.li[cont_level-1].off;
			if (offset == 0) {
				if ((ms->flags & MAGIC_DEBUG) != 0)
					fprintf(stderr,
					    "indirect *zero* offset\n");
				return 0;
			}
			if ((ms->flags & MAGIC_DEBUG) != 0)
				fprintf(stderr, "indirect +offs=%u\n", offset);
		}
		if (mcopy(ms, p, m->type, 0, s, offset, nbytes, m) == -1)
			return -1;
		ms->offset = offset;

		if ((ms->flags & MAGIC_DEBUG) != 0) {
			mdebug(offset, (char *)(void *)p,
			    sizeof(union VALUETYPE));
#ifndef COMPILE_ONLY
			file_mdump(m);
#endif
		}
	}

	/* Verify we have enough data to match magic type */
	switch (m->type) {
	case FILE_BYTE:
		if (OFFSET_OOB(nbytes, offset, 1))
			return 0;
		break;

	case FILE_SHORT:
	case FILE_BESHORT:
	case FILE_LESHORT:
		if (OFFSET_OOB(nbytes, offset, 2))
			return 0;
		break;

	case FILE_LONG:
	case FILE_BELONG:
	case FILE_LELONG:
	case FILE_MELONG:
	case FILE_DATE:
	case FILE_BEDATE:
	case FILE_LEDATE:
	case FILE_MEDATE:
	case FILE_LDATE:
	case FILE_BELDATE:
	case FILE_LELDATE:
	case FILE_MELDATE:
	case FILE_FLOAT:
	case FILE_BEFLOAT:
	case FILE_LEFLOAT:
		if (OFFSET_OOB(nbytes, offset, 4))
			return 0;
		break;

	case FILE_DOUBLE:
	case FILE_BEDOUBLE:
	case FILE_LEDOUBLE:
		if (OFFSET_OOB(nbytes, offset, 8))
			return 0;
		break;

	case FILE_STRING:
	case FILE_PSTRING:
	case FILE_SEARCH:
		if (OFFSET_OOB(nbytes, offset, m->vallen))
			return 0;
		break;

	case FILE_REGEX:
		if (nbytes < offset)
			return 0;
		break;

	case FILE_INDIRECT:
		if (offset == 0)
			return 0;
		if (nbytes < offset)
			return 0;
		sbuf = ms->o.buf;
		soffset = ms->offset;
		ms->o.buf = NULL;
		ms->offset = 0;
		rv = file_softmagic(ms, s + offset, nbytes - offset,
		    recursion_level, BINTEST, text);
		if ((ms->flags & MAGIC_DEBUG) != 0)
			fprintf(stderr, "indirect @offs=%u[%d]\n", offset, rv);
		rbuf = ms->o.buf;
		ms->o.buf = sbuf;
		ms->offset = soffset;
		if (rv == 1) {
			if ((ms->flags & (MAGIC_MIME|MAGIC_APPLE)) == 0 &&
			    file_printf(ms, F(ms, m, "%u"), offset) == -1) {
				free(rbuf);
				return -1;
			}
			if (file_printf(ms, "%s", rbuf) == -1) {
				free(rbuf);
				return -1;
			}
		}
		free(rbuf);
		return rv;

	case FILE_USE:
		if (nbytes < offset)
			return 0;
		sbuf = m->value.s;
		if (*sbuf == '^') {
			sbuf++;
			flip = !flip;
		}
		if (file_magicfind(ms, sbuf, &ml) == -1) {
			file_error(ms, 0, "cannot find entry `%s'", sbuf);
			return -1;
		}

		oneed_separator = *need_separator;
		if (m->flag & NOSPACE)
			*need_separator = 0;
		rv = match(ms, ml.magic, ml.nmagic, s, nbytes, offset + o,
		    mode, text, flip, recursion_level, printed_something,
		    need_separator, returnval);
		if (rv != 1)
		    *need_separator = oneed_separator;
		return rv;

	case FILE_NAME:
		if (file_printf(ms, "%s", m->desc) == -1)
			return -1;
		return 1;
	case FILE_DEFAULT:	/* nothing to check */
	case FILE_CLEAR:
	default:
		break;
	}
	if (!mconvert(ms, m, flip))
		return 0;
	return 1;
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.