ovl: fix wrong flags check in FS_IOC_FS[SG]ETXATTR ioctls

The ioctl argument was parsed as the wrong type.

Fixes: b21d9c435f93 ("ovl: support the FS_IOC_FS[SG]ETXATTR ioctls")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index 340a6ad45914fb01d59fbb386597d9f5d7830a95..75d8d00fa087ea517ca54a49a620de6f0813a43d 100644 (file)
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -409,37 +409,16 @@ static long ovl_real_ioctl(struct file *file, unsigned int cmd,
        return ret;
 }
 
-static unsigned int ovl_get_inode_flags(struct inode *inode)
-{
-       unsigned int flags = READ_ONCE(inode->i_flags);
-       unsigned int ovl_iflags = 0;
-
-       if (flags & S_SYNC)
-               ovl_iflags |= FS_SYNC_FL;
-       if (flags & S_APPEND)
-               ovl_iflags |= FS_APPEND_FL;
-       if (flags & S_IMMUTABLE)
-               ovl_iflags |= FS_IMMUTABLE_FL;
-       if (flags & S_NOATIME)
-               ovl_iflags |= FS_NOATIME_FL;
-
-       return ovl_iflags;
-}
-
 static long ovl_ioctl_set_flags(struct file *file, unsigned int cmd,
-                               unsigned long arg)
+                               unsigned long arg, unsigned int iflags)
 {
        long ret;
        struct inode *inode = file_inode(file);
-       unsigned int flags;
-       unsigned int old_flags;
+       unsigned int old_iflags;
 
        if (!inode_owner_or_capable(inode))
                return -EACCES;
 
-       if (get_user(flags, (int __user *) arg))
-               return -EFAULT;
-
        ret = mnt_want_write_file(file);
        if (ret)
                return ret;
@@ -448,8 +427,8 @@ static long ovl_ioctl_set_flags(struct file *file, unsigned int cmd,
 
        /* Check the capability before cred override */
        ret = -EPERM;
-       old_flags = ovl_get_inode_flags(inode);
-       if (((flags ^ old_flags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) &&
+       old_iflags = READ_ONCE(inode->i_flags);
+       if (((iflags ^ old_iflags) & (S_APPEND | S_IMMUTABLE)) &&
            !capable(CAP_LINUX_IMMUTABLE))
                goto unlock;
 
@@ -469,6 +448,63 @@ unlock:
 
 }
 
+static unsigned int ovl_fsflags_to_iflags(unsigned int flags)
+{
+       unsigned int iflags = 0;
+
+       if (flags & FS_SYNC_FL)
+               iflags |= S_SYNC;
+       if (flags & FS_APPEND_FL)
+               iflags |= S_APPEND;
+       if (flags & FS_IMMUTABLE_FL)
+               iflags |= S_IMMUTABLE;
+       if (flags & FS_NOATIME_FL)
+               iflags |= S_NOATIME;
+
+       return iflags;
+}
+
+static long ovl_ioctl_set_fsflags(struct file *file, unsigned int cmd,
+                                 unsigned long arg)
+{
+       unsigned int flags;
+
+       if (get_user(flags, (int __user *) arg))
+               return -EFAULT;
+
+       return ovl_ioctl_set_flags(file, cmd, arg,
+                                  ovl_fsflags_to_iflags(flags));
+}
+
+static unsigned int ovl_fsxflags_to_iflags(unsigned int xflags)
+{
+       unsigned int iflags = 0;
+
+       if (xflags & FS_XFLAG_SYNC)
+               iflags |= S_SYNC;
+       if (xflags & FS_XFLAG_APPEND)
+               iflags |= S_APPEND;
+       if (xflags & FS_XFLAG_IMMUTABLE)
+               iflags |= S_IMMUTABLE;
+       if (xflags & FS_XFLAG_NOATIME)
+               iflags |= S_NOATIME;
+
+       return iflags;
+}
+
+static long ovl_ioctl_set_fsxflags(struct file *file, unsigned int cmd,
+                                  unsigned long arg)
+{
+       struct fsxattr fa;
+
+       memset(&fa, 0, sizeof(fa));
+       if (copy_from_user(&fa, (void __user *) arg, sizeof(fa)))
+               return -EFAULT;
+
+       return ovl_ioctl_set_flags(file, cmd, arg,
+                                  ovl_fsxflags_to_iflags(fa.fsx_xflags));
+}
+
 static long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
        long ret;
@@ -480,8 +516,11 @@ static long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
                break;
 
        case FS_IOC_SETFLAGS:
+               ret = ovl_ioctl_set_fsflags(file, cmd, arg);
+               break;
+
        case FS_IOC_FSSETXATTR:
-               ret = ovl_ioctl_set_flags(file, cmd, arg);
+               ret = ovl_ioctl_set_fsxflags(file, cmd, arg);
                break;
 
        default: