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Commit c47ca32d authored by Dan Carpenter's avatar Dan Carpenter Committed by Chris Mason
Browse files

Btrfs: kfree()ing ERR_PTRs 



The "inherit" in btrfs_ioctl_snap_create_v2() and "vol_args" in
btrfs_ioctl_rm_dev() are ERR_PTRs so we can't call kfree() on them.

These kind of bugs are "One Err Bugs" where there is just one error
label that does everything.  I could set the "inherit = NULL" and keep
the single out label but it ends up being more complicated that way.  It
makes the code simpler to re-order the unwind so it's in the mirror
order of the allocation and introduce some new error labels.

Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: default avatarChris Mason <clm@fb.com>
parent dac5705c

fs/btrfs/ioctl.c

+15 −10
Original line number Diff line number Diff line
@@ -1703,7 +1703,7 @@ static noinline int btrfs_ioctl_snap_create_v2(struct file *file, 
	    ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |

	      BTRFS_SUBVOL_QGROUP_INHERIT)) {

		ret = -EOPNOTSUPP;

		goto out;

		goto free_args;

	}



	if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
@@ -1713,27 +1713,31 @@ static noinline int btrfs_ioctl_snap_create_v2(struct file *file, 
	if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {

		if (vol_args->size > PAGE_CACHE_SIZE) {

			ret = -EINVAL;

			goto out;

			goto free_args;

		}

		inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);

		if (IS_ERR(inherit)) {

			ret = PTR_ERR(inherit);

			goto out;

			goto free_args;

		}

	}



	ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,

					      vol_args->fd, subvol, ptr,

					      readonly, inherit);

	if (ret)

		goto free_inherit;



	if (ret == 0 && ptr &&

	    copy_to_user(arg +

	if (ptr && copy_to_user(arg +

				offsetof(struct btrfs_ioctl_vol_args_v2,

				  transid), ptr, sizeof(*ptr)))

					transid),

				ptr, sizeof(*ptr)))

		ret = -EFAULT;

out:

	kfree(vol_args);



free_inherit:

	kfree(inherit);

free_args:

	kfree(vol_args);

	return ret;

}
@@ -2653,7 +2657,7 @@ static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg) 
	vol_args = memdup_user(arg, sizeof(*vol_args));

	if (IS_ERR(vol_args)) {

		ret = PTR_ERR(vol_args);

		goto out;

		goto err_drop;

	}



	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
@@ -2671,6 +2675,7 @@ static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg) 


out:

	kfree(vol_args);

err_drop:

	mnt_drop_write_file(file);

	return ret;

}