Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

Pull UDF fix from Jan Kara:
 "A fix of a regression in UDF that got introduced in 4.6-rc1 by one of
  the charset encoding fixes"

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  udf: Fix conversion of 'dstring' fields to UTF8

3 files changed, 17 insertions, 5 deletions

diff --git a/fs/udf/super.c b/fs/udf/super.c
index fa92fe839fda..36661acaf33b 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -919,14 +919,14 @@ static int udf_load_pvoldesc(struct super_block *sb, sector_t block)
 #endif
 	}
 
-	ret = udf_CS0toUTF8(outstr, 31, pvoldesc->volIdent, 32);
+	ret = udf_dstrCS0toUTF8(outstr, 31, pvoldesc->volIdent, 32);
 	if (ret < 0)
 		goto out_bh;
 
 	strncpy(UDF_SB(sb)->s_volume_ident, outstr, ret);
 	udf_debug("volIdent[] = '%s'\n", UDF_SB(sb)->s_volume_ident);
 
-	ret = udf_CS0toUTF8(outstr, 127, pvoldesc->volSetIdent, 128);
+	ret = udf_dstrCS0toUTF8(outstr, 127, pvoldesc->volSetIdent, 128);
 	if (ret < 0)
 		goto out_bh;
 
diff --git a/fs/udf/udfdecl.h b/fs/udf/udfdecl.h
index 972b70625614..263829ef1873 100644
--- a/fs/udf/udfdecl.h
+++ b/fs/udf/udfdecl.h
@@ -212,7 +212,7 @@ extern int udf_get_filename(struct super_block *, const uint8_t *, int,
 			    uint8_t *, int);
 extern int udf_put_filename(struct super_block *, const uint8_t *, int,
 			    uint8_t *, int);
-extern int udf_CS0toUTF8(uint8_t *, int, const uint8_t *, int);
+extern int udf_dstrCS0toUTF8(uint8_t *, int, const uint8_t *, int);
 
 /* ialloc.c */
 extern void udf_free_inode(struct inode *);
diff --git a/fs/udf/unicode.c b/fs/udf/unicode.c
index 3ff42f4437f3..695389a4fc23 100644
--- a/fs/udf/unicode.c
+++ b/fs/udf/unicode.c
@@ -335,9 +335,21 @@ try_again:
 	return u_len;
 }
 
-int udf_CS0toUTF8(uint8_t *utf_o, int o_len, const uint8_t *ocu_i, int i_len)
+int udf_dstrCS0toUTF8(uint8_t *utf_o, int o_len,
+		      const uint8_t *ocu_i, int i_len)
 {
-	return udf_name_from_CS0(utf_o, o_len, ocu_i, i_len,
+	int s_len = 0;
+
+	if (i_len > 0) {
+		s_len = ocu_i[i_len - 1];
+		if (s_len >= i_len) {
+			pr_err("incorrect dstring lengths (%d/%d)\n",
+			       s_len, i_len);
+			return -EINVAL;
+		}
+	}
+
+	return udf_name_from_CS0(utf_o, o_len, ocu_i, s_len,
 				 udf_uni2char_utf8, 0);
 }