Message ID | 20190108114209.2137-1-fdmanana@kernel.org (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | [v2] Btrfs: do not overwrite error return value in the device replace ioctl | expand |
On Tue, Jan 08, 2019 at 11:42:09AM +0000, fdmanana@kernel.org wrote: > From: Filipe Manana <fdmanana@suse.com> > > If the call to btrfs_dev_replace_by_ioctl() failed we would overwrite the > error returned to user space with -EFAULT if the call to copy_to_user() > failed as well. Fix that by calling copy_to_user() only if no error > happened before or a device replace operation was canceled. > > Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 8dbb4ed07da1..0db60bfee99a 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -4462,7 +4462,7 @@ static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info, break; } - if (copy_to_user(arg, p, sizeof(*p))) + if ((ret == 0 || ret == -ECANCELED) && copy_to_user(arg, p, sizeof(*p))) ret = -EFAULT; out: kfree(p);