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>

1 files changed, 65 insertions, 26 deletions

diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index 340a6ad45914..75d8d00fa087 100644
--- 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: