svn commit: r328029 - head/stand/efi/libefi

[Warner Losh]

Author: imp
Date: Mon Jan 15 22:17:15 2018
New Revision: 328029
URL: https://svnweb.freebsd.org/changeset/base/328029

Log:
  When returning an error and freeing allocated memory from ucs2_to_utf8
  and utf8_to_ucs2, be sure to NULL out the return pointer too, rather
  than return a pointer to free memory.
  
  Sponsored by: Netflix
  Differential Revision: https://reviews.freebsd.org/D13917

Modified:
  head/stand/efi/libefi/efichar.c

Modified: head/stand/efi/libefi/efichar.c
==============================================================================
--- head/stand/efi/libefi/efichar.c	Mon Jan 15 21:59:20 2018	(r328028)
+++ head/stand/efi/libefi/efichar.c	Mon Jan 15 22:17:15 2018	(r328029)
@@ -116,8 +116,10 @@ ucs2_to_utf8(const efi_char *nm, char **name)
 
 	if (len >= sz) {
 		/* Absent bugs, we'll never return EOVERFLOW */
-		if (freeit)
+		if (freeit) {
 			free(*name);
+			*name = NULL;
+		}
 		return (EOVERFLOW);
 	}
 	*cp++ = '\0';
@@ -150,11 +152,8 @@ utf8_to_ucs2(const char *name, efi_char **nmp, size_t 
 		 */
 		if ((c & 0xc0) != 0x80) {
 			/* Initial characters. */
-			if (bytes != 0) {
-				if (freeit)
-					free(nm);
-				return (EILSEQ);
-			}
+			if (bytes != 0)
+				goto ilseq;
 			if ((c & 0xf8) == 0xf0) {
 				ucs4 = c & 0x07;
 				bytes = 3;
@@ -173,29 +172,31 @@ utf8_to_ucs2(const char *name, efi_char **nmp, size_t 
 			if (bytes > 0) {
 				ucs4 = (ucs4 << 6) + (c & 0x3f);
 				bytes--;
-			} else if (bytes == 0) {
-				if (freeit)
-					free(nm);
-				return (EILSEQ);
-			}
+			} else if (bytes == 0)
+				goto ilseq;
 		}
 		if (bytes == 0) {
-			if (ucs4 > 0xffff) {
-				if (freeit)
-					free(nm);
-				return (EILSEQ);
-			}
+			if (ucs4 > 0xffff)
+				goto ilseq;
 			*nm++ = (efi_char)ucs4;
 			sz -= 2;
 		}
 	}
 	if (sz < 2) {
-		if (freeit)
+		if (freeit) {
 			free(nm);
+			*nmp = NULL;
+		}
 		return (EDOOFUS);
 	}
 	sz -= 2;
 	*nm = 0;
 	*len -= sz;
 	return (0);
+ilseq:
+	if (freeit) {
+		free(nm);
+		*nmp = NULL;
+	}
+	return (EILSEQ);
 }