Upstream-Author: Christos Zoulas <christos@zoulas.com>
Description:
 prevent infinite recursion.
 count indirect recursion as recursion.

Upstream commit IDs:
    3c081560c23f20b2985c285338b52c7aae9fdb0f
    cc9e74dfeca5265ad725acc926ef0b8d2a18ee70

Backport for 5.11: Christoph Biedl <debian.axhn@manchmal.in-ulm.de>

--- a/src/softmagic.c
+++ b/src/softmagic.c
@@ -43,9 +43,9 @@
 
 
 private int match(struct magic_set *, struct magic *, uint32_t,
-    const unsigned char *, size_t, int, int);
+    const unsigned char *, size_t, int, int, int);
 private int mget(struct magic_set *, const unsigned char *,
-    struct magic *, size_t, unsigned int, int);
+    struct magic *, size_t, unsigned int, int, int);
 private int magiccheck(struct magic_set *, struct magic *);
 private int32_t mprint(struct magic_set *, struct magic *);
 private int32_t moffset(struct magic_set *, struct magic *);
@@ -67,13 +67,13 @@
 /*ARGSUSED1*/		/* nbytes passed for regularity, maybe need later */
 protected int
 file_softmagic(struct magic_set *ms, const unsigned char *buf, size_t nbytes,
-    int mode, int text)
+    size_t level, int mode, int text)
 {
 	struct mlist *ml;
 	int rv;
 	for (ml = ms->mlist->next; ml != ms->mlist; ml = ml->next)
 		if ((rv = match(ms, ml->magic, ml->nmagic, buf, nbytes, mode,
-		    text)) != 0)
+		    text, level)) != 0)
 			return rv;
 
 	return 0;
@@ -108,7 +108,8 @@
  */
 private int
 match(struct magic_set *ms, struct magic *magic, uint32_t nmagic,
-    const unsigned char *s, size_t nbytes, int mode, int text)
+    const unsigned char *s, size_t nbytes, int mode, int text,
+    int recursion_level)
 {
 	uint32_t magindex = 0;
 	unsigned int cont_level = 0;
@@ -140,7 +141,7 @@
 		ms->line = m->lineno;
 
 		/* if main entry matches, print it... */
-		switch (mget(ms, s, m, nbytes, cont_level, text)) {
+		switch (mget(ms, s, m, nbytes, cont_level, text, recursion_level + 1)) {
 		case -1:
 			return -1;
 		case 0:
@@ -223,7 +224,7 @@
 					continue;
 			}
 #endif
-			switch (mget(ms, s, m, nbytes, cont_level, text)) {
+			switch (mget(ms, s, m, nbytes, cont_level, text, recursion_level + 1)) {
 			case -1:
 				return -1;
 			case 0:
@@ -1018,12 +1019,18 @@
 
 private int
 mget(struct magic_set *ms, const unsigned char *s,
-    struct magic *m, size_t nbytes, unsigned int cont_level, int text)
+    struct magic *m, size_t nbytes, unsigned int cont_level, int text,
+    int recursion_level)
 {
 	uint32_t offset = ms->offset;
 	uint32_t count = m->str_range;
 	union VALUETYPE *p = &ms->ms_value;
 
+        if (recursion_level >= 20) {
+                file_error(ms, 0, "recursion nesting exceeded");
+                return -1;
+        }
+
 	if (mcopy(ms, p, m->type, m->flag & INDIR, s, offset, nbytes, count) == -1)
 		return -1;
 
@@ -1577,13 +1584,15 @@
 		break;
 
 	case FILE_INDIRECT:
+		if (offset == 0)
+			return 0;
 	  	if ((ms->flags & (MAGIC_MIME|MAGIC_APPLE)) == 0 &&
 		    file_printf(ms, "%s", m->desc) == -1)
 			return -1;
 		if (nbytes < offset)
 			return 0;
 		return file_softmagic(ms, s + offset, nbytes - offset,
-		    BINTEST, text);
+		    recursion_level, BINTEST, text);
 
 	case FILE_DEFAULT:	/* nothing to check */
 	default:
--- a/src/ascmagic.c
+++ b/src/ascmagic.c
@@ -147,7 +147,7 @@
 		    == NULL)
 			goto done;
 		if ((rv = file_softmagic(ms, utf8_buf,
-		    (size_t)(utf8_end - utf8_buf), TEXTTEST, text)) == 0)
+		    (size_t)(utf8_end - utf8_buf), 0, TEXTTEST, text)) == 0)
 			rv = -1;
 	}
 
--- a/src/file.h
+++ b/src/file.h
@@ -414,7 +414,7 @@
     unichar **, size_t *, const char **, const char **, const char **);
 protected int file_is_tar(struct magic_set *, const unsigned char *, size_t);
 protected int file_softmagic(struct magic_set *, const unsigned char *, size_t,
-    int, int);
+    size_t, int, int);
 protected struct mlist *file_apprentice(struct magic_set *, const char *, int);
 protected uint64_t file_signextend(struct magic_set *, struct magic *,
     uint64_t);
--- a/src/funcs.c
+++ b/src/funcs.c
@@ -228,7 +228,7 @@
 
 	/* try soft magic tests */
 	if ((ms->flags & MAGIC_NO_CHECK_SOFT) == 0)
-		if ((m = file_softmagic(ms, ubuf, nb, BINTEST,
+		if ((m = file_softmagic(ms, ubuf, nb, 0, BINTEST,
 		    looks_text)) != 0) {
 			if ((ms->flags & MAGIC_DEBUG) != 0)
 				(void)fprintf(stderr, "softmagic %d\n", m);