Fix multiple vulnerabilities in file(1) and libmagic(3).

Security:	FreeBSD-SA-14:28.file
Security:	CVE-2014-3710, CVE-2014-8116, CVE-2014-8117

5 files changed, 114 insertions, 26 deletions

diff --git a/contrib/file/src/elfclass.h b/contrib/file/src/elfclass.h
index 010958a..0826ce3 100644
--- a/contrib/file/src/elfclass.h
+++ b/contrib/file/src/elfclass.h
@@ -35,10 +35,12 @@
 	switch (type) {
 #ifdef ELFCORE
 	case ET_CORE:
+		phnum = elf_getu16(swap, elfhdr.e_phnum);
+		if (phnum > MAX_PHNUM)
+			return toomany(ms, "program", phnum);
 		flags |= FLAGS_IS_CORE;
 		if (dophn_core(ms, clazz, swap, fd,
-		    (off_t)elf_getu(swap, elfhdr.e_phoff),
-		    elf_getu16(swap, elfhdr.e_phnum), 
+		    (off_t)elf_getu(swap, elfhdr.e_phoff), phnum,
 		    (size_t)elf_getu16(swap, elfhdr.e_phentsize),
 		    fsize, &flags) == -1)
 			return -1;
@@ -46,18 +48,24 @@
 #endif
 	case ET_EXEC:
 	case ET_DYN:
+		phnum = elf_getu16(swap, elfhdr.e_phnum);
+		if (phnum > MAX_PHNUM)
+			return toomany(ms, "program", phnum);
+		shnum = elf_getu16(swap, elfhdr.e_shnum);
+		if (shnum > MAX_SHNUM)
+			return toomany(ms, "section", shnum);
 		if (dophn_exec(ms, clazz, swap, fd,
-		    (off_t)elf_getu(swap, elfhdr.e_phoff),
-		    elf_getu16(swap, elfhdr.e_phnum), 
+		    (off_t)elf_getu(swap, elfhdr.e_phoff), phnum,
 		    (size_t)elf_getu16(swap, elfhdr.e_phentsize),
-		    fsize, &flags, elf_getu16(swap, elfhdr.e_shnum))
-		    == -1)
+		    fsize, &flags, shnum) == -1)
 			return -1;
 		/*FALLTHROUGH*/
 	case ET_REL:
+		shnum = elf_getu16(swap, elfhdr.e_shnum);
+		if (shnum > MAX_SHNUM)
+			return toomany(ms, "section", shnum);
 		if (doshn(ms, clazz, swap, fd,
-		    (off_t)elf_getu(swap, elfhdr.e_shoff),
-		    elf_getu16(swap, elfhdr.e_shnum),
+		    (off_t)elf_getu(swap, elfhdr.e_shoff), shnum,
 		    (size_t)elf_getu16(swap, elfhdr.e_shentsize),
 		    fsize, &flags, elf_getu16(swap, elfhdr.e_machine),
 		    (int)elf_getu16(swap, elfhdr.e_shstrndx)) == -1)
diff --git a/contrib/file/src/file.h b/contrib/file/src/file.h
index 67a2568..1a652a8 100644
--- a/contrib/file/src/file.h
+++ b/contrib/file/src/file.h
@@ -482,6 +482,14 @@ protected int file_regexec(file_regex_t *, const char *, size_t, regmatch_t *,
 protected void file_regfree(file_regex_t *);
 protected void file_regerror(file_regex_t *, int, struct magic_set *);
 
+typedef struct {
+	char *buf;
+	uint32_t offset;
+} file_pushbuf_t;
+
+protected file_pushbuf_t *file_push_buffer(struct magic_set *);
+protected char  *file_pop_buffer(struct magic_set *, file_pushbuf_t *);
+
 #ifndef COMPILE_ONLY
 extern const char *file_names[];
 extern const size_t file_nnames;
diff --git a/contrib/file/src/funcs.c b/contrib/file/src/funcs.c
index 3a2f67c..7e7d2e7 100644
--- a/contrib/file/src/funcs.c
+++ b/contrib/file/src/funcs.c
@@ -491,3 +491,43 @@ file_regerror(file_regex_t *rx, int rc, struct magic_set *ms)
 	file_magerror(ms, "regex error %d for `%s', (%s)", rc, rx->pat,
 	    errmsg);
 }
+
+protected file_pushbuf_t *
+file_push_buffer(struct magic_set *ms)
+{
+	file_pushbuf_t *pb;
+
+	if (ms->event_flags & EVENT_HAD_ERR)
+		return NULL;
+
+	if ((pb = (CAST(file_pushbuf_t *, malloc(sizeof(*pb))))) == NULL)
+		return NULL;
+
+	pb->buf = ms->o.buf;
+	pb->offset = ms->offset;
+
+	ms->o.buf = NULL;
+	ms->offset = 0;
+
+	return pb;
+}
+
+protected char *
+file_pop_buffer(struct magic_set *ms, file_pushbuf_t *pb)
+{
+	char *rbuf;
+
+	if (ms->event_flags & EVENT_HAD_ERR) {
+		free(pb->buf);
+		free(pb);
+		return NULL;
+	}
+
+	rbuf = ms->o.buf;
+
+	ms->o.buf = pb->buf;
+	ms->offset = pb->offset;
+
+	free(pb);
+	return rbuf;
+}
diff --git a/contrib/file/src/readelf.c b/contrib/file/src/readelf.c
index ede7e0c..55b7e98 100644
--- a/contrib/file/src/readelf.c
+++ b/contrib/file/src/readelf.c
@@ -60,6 +60,18 @@ private uint16_t getu16(int, uint16_t);
 private uint32_t getu32(int, uint32_t);
 private uint64_t getu64(int, uint64_t);
 
+#define MAX_PHNUM	256
+#define	MAX_SHNUM	1024
+
+private int
+toomany(struct magic_set *ms, const char *name, uint16_t num)
+{
+	if (file_printf(ms, ", too many %s header sections (%u)", name, num
+	    ) == -1)
+		return -1;
+	return 0;
+}
+
 private uint16_t
 getu16(int swap, uint16_t value)
 {
@@ -477,6 +489,13 @@ donote(struct magic_set *ms, void *vbuf, size_t offset, size_t size,
 	uint32_t namesz, descsz;
 	unsigned char *nbuf = CAST(unsigned char *, vbuf);
 
+	if (xnh_sizeof + offset > size) {
+		/*
+		 * We're out of note headers.
+		 */
+		return xnh_sizeof + offset;
+	}
+
 	(void)memcpy(xnh_addr, &nbuf[offset], xnh_sizeof);
 	offset += xnh_sizeof;
 
@@ -492,13 +511,13 @@ donote(struct magic_set *ms, void *vbuf, size_t offset, size_t size,
 	if (namesz & 0x80000000) {
 	    (void)file_printf(ms, ", bad note name size 0x%lx",
 		(unsigned long)namesz);
-	    return offset;
+	    return 0;
 	}
 
 	if (descsz & 0x80000000) {
 	    (void)file_printf(ms, ", bad note description size 0x%lx",
 		(unsigned long)descsz);
-	    return offset;
+	    return 0;
 	}
 
 
@@ -900,6 +919,7 @@ doshn(struct magic_set *ms, int clazz, int swap, int fd, off_t off, int num,
 	Elf32_Shdr sh32;
 	Elf64_Shdr sh64;
 	int stripped = 1;
+	size_t nbadcap = 0;
 	void *nbuf;
 	off_t noff, coff, name_off;
 	uint64_t cap_hw1 = 0;	/* SunOS 5.x hardware capabilites */
@@ -988,6 +1008,8 @@ doshn(struct magic_set *ms, int clazz, int swap, int fd, off_t off, int num,
 				goto skip;
 			}
 
+			if (nbadcap > 5)
+				break;
 			if (lseek(fd, xsh_offset, SEEK_SET) == (off_t)-1) {
 				file_badseek(ms);
 				return -1;
@@ -1053,6 +1075,8 @@ doshn(struct magic_set *ms, int clazz, int swap, int fd, off_t off, int num,
 					    (unsigned long long)xcap_tag,
 					    (unsigned long long)xcap_val) == -1)
 						return -1;
+					if (nbadcap++ > 2)
+						coff = xsh_size;
 					break;
 				}
 			}
@@ -1233,7 +1257,7 @@ file_tryelf(struct magic_set *ms, int fd, const unsigned char *buf,
 	int flags = 0;
 	Elf32_Ehdr elf32hdr;
 	Elf64_Ehdr elf64hdr;
-	uint16_t type;
+	uint16_t type, phnum, shnum;
 
 	if (ms->flags & (MAGIC_MIME|MAGIC_APPLE))
 		return 0;
diff --git a/contrib/file/src/softmagic.c b/contrib/file/src/softmagic.c
index ed97aa7..b0f193d 100644
--- a/contrib/file/src/softmagic.c
+++ b/contrib/file/src/softmagic.c
@@ -67,6 +67,9 @@ private void cvt_32(union VALUETYPE *, const struct magic *);
 private void cvt_64(union VALUETYPE *, const struct magic *);
 
 #define OFFSET_OOB(n, o, i)	((n) < (o) || (i) > ((n) - (o)))
+
+#define MAX_RECURSION_LEVEL	10
+
 /*
  * softmagic - lookup one file in parsed, in-memory copy of database
  * Passed the name and FILE * of one file to be typed.
@@ -1193,14 +1196,15 @@ mget(struct magic_set *ms, const unsigned char *s, struct magic *m,
     int flip, int recursion_level, int *printed_something,
     int *need_separator, int *returnval)
 {
-	uint32_t soffset, offset = ms->offset;
+	uint32_t offset = ms->offset;
 	uint32_t lhs;
+	file_pushbuf_t *pb;
 	int rv, oneed_separator, in_type;
-	char *sbuf, *rbuf;
+	char *rbuf;
 	union VALUETYPE *p = &ms->ms_value;
 	struct mlist ml;
 
-	if (recursion_level >= 20) {
+	if (recursion_level >= MAX_RECURSION_LEVEL) {
 		file_error(ms, 0, "recursion nesting exceeded");
 		return -1;
 	}
@@ -1644,19 +1648,23 @@ mget(struct magic_set *ms, const unsigned char *s, struct magic *m,
 	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;
+
+		if ((pb = file_push_buffer(ms)) == NULL)
+			return -1;
+
 		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;
+
+		rbuf = file_pop_buffer(ms, pb);
+		if (rbuf == NULL && ms->event_flags & EVENT_HAD_ERR)
+			return -1;
+
 		if (rv == 1) {
 			if ((ms->flags & (MAGIC_MIME|MAGIC_APPLE)) == 0 &&
 			    file_printf(ms, F(ms, m, "%u"), offset) == -1) {
@@ -1674,13 +1682,13 @@ mget(struct magic_set *ms, const unsigned char *s, struct magic *m,
 	case FILE_USE:
 		if (nbytes < offset)
 			return 0;
-		sbuf = m->value.s;
-		if (*sbuf == '^') {
-			sbuf++;
+		rbuf = m->value.s;
+		if (*rbuf == '^') {
+			rbuf++;
 			flip = !flip;
 		}
-		if (file_magicfind(ms, sbuf, &ml) == -1) {
-			file_error(ms, 0, "cannot find entry `%s'", sbuf);
+		if (file_magicfind(ms, rbuf, &ml) == -1) {
+			file_error(ms, 0, "cannot find entry `%s'", rbuf);
 			return -1;
 		}