Merge tag 'exfat-for-6.18-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/exfat

Pull exfat fixes from Namjae Jeon:

 - Fix out-of-bounds in FS_IOC_SETFSLABEL

 - Add validation for stream entry size to prevent infinite loop

* tag 'exfat-for-6.18-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/exfat:
  exfat: fix out-of-bounds in exfat_nls_to_ucs2()
  exfat: fix improper check of dentry.stream.valid_size

Author: torvalds

fs/exfat/exfat_fs.h

@@ -29,7 +29,6 @@ enum exfat_error_mode {
 enum {
 	NLS_NAME_NO_LOSSY =	0,	/* no lossy */
 	NLS_NAME_LOSSY =	1 << 0,	/* just detected incorrect filename(s) */
-	NLS_NAME_OVERLEN =	1 << 1,	/* the length is over than its limit */
 };
 
 #define EXFAT_HASH_BITS		8

fs/exfat/file.c

@@ -509,8 +509,8 @@ static int exfat_ioctl_get_volume_label(struct super_block *sb, unsigned long ar
 static int exfat_ioctl_set_volume_label(struct super_block *sb,
 					unsigned long arg)
 {
-	int ret = 0, lossy;
-	char label[FSLABEL_MAX];
+	int ret = 0, lossy, label_len;
+	char label[FSLABEL_MAX] = {0};
 	struct exfat_uni_name uniname;
 
 	if (!capable(CAP_SYS_ADMIN))
@@ -520,8 +520,9 @@ static int exfat_ioctl_set_volume_label(struct super_block *sb,
 		return -EFAULT;
 
 	memset(&uniname, 0, sizeof(uniname));
+	label_len = strnlen(label, FSLABEL_MAX - 1);
 	if (label[0]) {
-		ret = exfat_nls_to_utf16(sb, label, FSLABEL_MAX,
+		ret = exfat_nls_to_utf16(sb, label, label_len,
 					 &uniname, &lossy);
 		if (ret < 0)
 			return ret;

fs/exfat/namei.c

@@ -442,7 +442,7 @@ static int __exfat_resolve_path(struct inode *inode, const unsigned char *path,
 		return namelen; /* return error value */
 
 	if ((lossy && !lookup) || !namelen)
-		return (lossy & NLS_NAME_OVERLEN) ? -ENAMETOOLONG : -EINVAL;
+		return -EINVAL;
 
 	return 0;
 }
@@ -642,10 +642,14 @@ static int exfat_find(struct inode *dir, const struct qstr *qname,
 
 	info->type = exfat_get_entry_type(ep);
 	info->attr = le16_to_cpu(ep->dentry.file.attr);
-	info->size = le64_to_cpu(ep2->dentry.stream.valid_size);
 	info->valid_size = le64_to_cpu(ep2->dentry.stream.valid_size);
 	info->size = le64_to_cpu(ep2->dentry.stream.size);
 
+	if (info->valid_size < 0) {
+		exfat_fs_error(sb, "data valid size is invalid(%lld)", info->valid_size);
+		return -EIO;
+	}
+
 	if (unlikely(EXFAT_B_TO_CLU_ROUND_UP(info->size, sbi) > sbi->used_clusters)) {
 		exfat_fs_error(sb, "data size is invalid(%lld)", info->size);
 		return -EIO;

fs/exfat/nls.c

@@ -616,9 +616,6 @@ static int exfat_nls_to_ucs2(struct super_block *sb,
 		unilen++;
 	}
 
-	if (p_cstring[i] != '\0')
-		lossy |= NLS_NAME_OVERLEN;
-
 	*uniname = '\0';
 	p_uniname->name_len = unilen;
 	p_uniname->name_hash = exfat_calc_chksum16(upname, unilen << 1, 0,