From a88baed8dd64c3f77ee5070029d305489ad63743 Mon Sep 17 00:00:00 2001
From: Jeremy Allison <jra@samba.org>
Date: Sat, 7 Jun 2014 21:51:44 -0700
Subject: [PATCH] s3: smbd - fix processing of packets with invalid DOS charset
 conversions.

Bug 10654 - Segmentation fault in smbd_marshall_dir_entry()'s SMB_FIND_FILE_UNIX handler

https://bugzilla.samba.org/show_bug.cgi?id=10654

Signed-off-by: Jeremy Allison <jra@samba.org>

CVE-2014-3493
---
 source3/lib/charcnv.c   | 26 +++++++++++++++++---------
 source3/libsmb/clirap.c |  4 ++--
 source3/smbd/lanman.c   |  4 ++--
 3 files changed, 21 insertions(+), 13 deletions(-)

diff --git a/source3/lib/charcnv.c b/source3/lib/charcnv.c
index 71d2c3aba56..2189812e2ab 100644
--- a/source3/lib/charcnv.c
+++ b/source3/lib/charcnv.c
@@ -46,9 +46,9 @@ void gfree_charcnv(void)
  **/
 size_t push_ascii(void *dest, const char *src, size_t dest_len, int flags)
 {
-	size_t src_len = strlen(src);
+	size_t src_len = 0;
 	char *tmpbuf = NULL;
-	size_t size;
+	size_t size = 0;
 	bool ret;
 
 	/* No longer allow a length of -1. */
@@ -62,24 +62,32 @@ size_t push_ascii(void *dest, const char *src, size_t dest_len, int flags)
 			smb_panic("malloc fail");
 		}
 		if (!strupper_m(tmpbuf)) {
+			if ((flags & (STR_TERMINATE|STR_TERMINATE_ASCII)) &&
+					dest &&
+					dest_len > 0) {
+				*(char *)dest = 0;
+			}
 			SAFE_FREE(tmpbuf);
-			return (size_t)-1;
+			return 0;
 		}
 		src = tmpbuf;
 	}
 
+	src_len = strlen(src);
 	if (flags & (STR_TERMINATE | STR_TERMINATE_ASCII)) {
 		src_len++;
 	}
 
 	ret = convert_string(CH_UNIX, CH_DOS, src, src_len, dest, dest_len, &size);
-	if (ret == false &&
-			(flags & (STR_TERMINATE | STR_TERMINATE_ASCII))
-			&& dest_len > 0) {
-		((char *)dest)[0] = '\0';
-	}
 	SAFE_FREE(tmpbuf);
-	return ret ? size : (size_t)-1;
+	if (ret == false) {
+		if ((flags & (STR_TERMINATE | STR_TERMINATE_ASCII)) &&
+				dest_len > 0) {
+			((char *)dest)[0] = '\0';
+		}
+		return 0;
+	}
+	return size;
 }
 
 /********************************************************************
diff --git a/source3/libsmb/clirap.c b/source3/libsmb/clirap.c
index 036919f903c..64e3767c129 100644
--- a/source3/libsmb/clirap.c
+++ b/source3/libsmb/clirap.c
@@ -327,7 +327,7 @@ bool cli_NetServerEnum(struct cli_state *cli, char *workgroup, uint32 stype,
 				sizeof(param) - PTR_DIFF(p,param) - 1,
 				STR_TERMINATE|STR_UPPER);
 
-		if (len == (size_t)-1) {
+		if (len == 0) {
 			SAFE_FREE(last_entry);
 			return false;
 		}
@@ -339,7 +339,7 @@ bool cli_NetServerEnum(struct cli_state *cli, char *workgroup, uint32 stype,
 					sizeof(param) - PTR_DIFF(p,param) - 1,
 					STR_TERMINATE);
 
-			if (len == (size_t)-1) {
+			if (len == 0) {
 				SAFE_FREE(last_entry);
 				return false;
 			}
diff --git a/source3/smbd/lanman.c b/source3/smbd/lanman.c
index 1b734a7299e..0a0ab6b9754 100644
--- a/source3/smbd/lanman.c
+++ b/source3/smbd/lanman.c
@@ -128,7 +128,7 @@ static int CopyExpanded(connection_struct *conn,
 		return 0;
 	}
 	l = push_ascii(*dst,buf,*p_space_remaining, STR_TERMINATE);
-	if (l == -1) {
+	if (l == 0) {
 		return 0;
 	}
 	(*dst) += l;
@@ -143,7 +143,7 @@ static int CopyAndAdvance(char **dst, char *src, int *n)
 		return 0;
 	}
 	l = push_ascii(*dst,src,*n, STR_TERMINATE);
-	if (l == -1) {
+	if (l == 0) {
 		return 0;
 	}
 	(*dst) += l;
-- 
2.34.1