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diff --git a/src/softmagic.c b/src/softmagic.c
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index 56f09ee..8d08cad 100644
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--- a/src/softmagic.c
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+++ b/src/softmagic.c
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@@ -61,6 +61,7 @@ private void cvt_16(union VALUETYPE *, const struct magic *);
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 private void cvt_32(union VALUETYPE *, const struct magic *);
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 private void cvt_64(union VALUETYPE *, const struct magic *);
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+#define OFFSET_OOB(n, o, i)	((n) < (o) || (i) > ((n) - (o)))
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 /*
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  * softmagic - lookup one file in parsed, in-memory copy of database
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  * Passed the name and FILE * of one file to be typed.
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@@ -1081,7 +1082,7 @@ mget(struct magic_set *ms, const unsigned char *s,
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 		}
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 		switch (m->in_type) {
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 		case FILE_BYTE:
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-			if (nbytes < (offset + 1))
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+			if (OFFSET_OOB(nbytes, offset, 1))
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 				return 0;
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 			if (off) {
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 				switch (m->in_op & FILE_OPS_MASK) {
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@@ -1116,7 +1117,8 @@ mget(struct magic_set *ms, const unsigned char *s,
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 				offset = ~offset;
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 			break;
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 		case FILE_BESHORT:
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-			if (nbytes < (offset + 2))
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+			
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+			if (OFFSET_OOB(nbytes, offset, 2))
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 				return 0;
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 			if (off) {
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 				switch (m->in_op & FILE_OPS_MASK) {
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@@ -1168,7 +1170,7 @@ mget(struct magic_set *ms, const unsigned char *s,
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 				offset = ~offset;
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 			break;
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 		case FILE_LESHORT:
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-			if (nbytes < (offset + 2))
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+			if (OFFSET_OOB(nbytes, offset, 2))
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 				return 0;
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 			if (off) {
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 				switch (m->in_op & FILE_OPS_MASK) {
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@@ -1220,7 +1222,7 @@ mget(struct magic_set *ms, const unsigned char *s,
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 				offset = ~offset;
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 			break;
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 		case FILE_SHORT:
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-			if (nbytes < (offset + 2))
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+			if (OFFSET_OOB(nbytes, offset, 2))
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 				return 0;
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 			if (off) {
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 				switch (m->in_op & FILE_OPS_MASK) {
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@@ -1257,7 +1259,7 @@ mget(struct magic_set *ms, const unsigned char *s,
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 			break;
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 		case FILE_BELONG:
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 		case FILE_BEID3:
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-			if (nbytes < (offset + 4))
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+			if (OFFSET_OOB(nbytes, offset, 4))
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 				return 0;
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 			if (off) {
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 				switch (m->in_op & FILE_OPS_MASK) {
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@@ -1328,7 +1330,7 @@ mget(struct magic_set *ms, const unsigned char *s,
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 			break;
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 		case FILE_LELONG:
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 		case FILE_LEID3:
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-			if (nbytes < (offset + 4))
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+			if (OFFSET_OOB(nbytes, offset, 4))
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 				return 0;
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 			if (off) {
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 				switch (m->in_op & FILE_OPS_MASK) {
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@@ -1398,7 +1400,7 @@ mget(struct magic_set *ms, const unsigned char *s,
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 				offset = ~offset;
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 			break;
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 		case FILE_MELONG:
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-			if (nbytes < (offset + 4))
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+			if (OFFSET_OOB(nbytes, offset, 4))
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 				return 0;
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 			if (off) {
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 				switch (m->in_op & FILE_OPS_MASK) {
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@@ -1468,7 +1470,7 @@ mget(struct magic_set *ms, const unsigned char *s,
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 				offset = ~offset;
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 			break;
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 		case FILE_LONG:
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-			if (nbytes < (offset + 4))
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+			if (OFFSET_OOB(nbytes, offset, 4))
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 				return 0;
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 			if (off) {
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 				switch (m->in_op & FILE_OPS_MASK) {
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@@ -1535,14 +1537,14 @@ mget(struct magic_set *ms, const unsigned char *s,
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 	/* Verify we have enough data to match magic type */
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 	switch (m->type) {
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 	case FILE_BYTE:
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-		if (nbytes < (offset + 1)) /* should alway be true */
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+		if (OFFSET_OOB(nbytes, offset, 1))
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 			return 0;
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 		break;
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 	case FILE_SHORT:
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 	case FILE_BESHORT:
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 	case FILE_LESHORT:
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-		if (nbytes < (offset + 2))
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+		if (OFFSET_OOB(nbytes, offset, 2))
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 			return 0;
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 		break;
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@@ -1561,26 +1563,26 @@ mget(struct magic_set *ms, const unsigned char *s,
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 	case FILE_FLOAT:
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 	case FILE_BEFLOAT:
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 	case FILE_LEFLOAT:
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-		if (nbytes < (offset + 4))
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+		if (OFFSET_OOB(nbytes, offset, 4))
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 			return 0;
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 		break;
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 	case FILE_DOUBLE:
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 	case FILE_BEDOUBLE:
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 	case FILE_LEDOUBLE:
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-		if (nbytes < (offset + 8))
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+		if (OFFSET_OOB(nbytes, offset, 8))
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 			return 0;
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 		break;
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 	case FILE_STRING:
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 	case FILE_PSTRING:
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 	case FILE_SEARCH:
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-		if (nbytes < (offset + m->vallen))
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+		if (OFFSET_OOB(nbytes, offset, m->vallen))
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 			return 0;
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 		break;
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 	case FILE_REGEX:
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-		if (nbytes < offset)
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+		if (OFFSET_OOB(nbytes, offset, 0))
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 			return 0;
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 		break;
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