From: Filipe Manana Date: Tue, 8 Jan 2019 11:42:09 +0000 (+0000) Subject: Btrfs: do not overwrite error return value in the device replace ioctl X-Git-Tag: v5.1-rc1~47^2~79 X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=d3a53286c191c3d598eae09a68bb99a0db4e2466;p=tomoyo%2Ftomoyo-test1.git Btrfs: do not overwrite error return value in the device replace ioctl 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 Reviewed-by: David Sterba Signed-off-by: David Sterba --- diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 816fa7dce79f..b07b19acdbb1 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -4475,7 +4475,7 @@ 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);