Re: [PATCH v1 0/2] Refactor return value of two lsm hooks

[Casey Schaufler <casey@schaufler-ca.com>]

On 7/23/2024 7:06 PM, Xu Kuohai wrote:
> From: Xu Kuohai <xukuohai@huawei.com>
>
> The BPF LSM program may cause a kernel panic if it returns an
> unexpected value, such as a positive value on the hook
> file_alloc_security.
>
> To fix it, series [1] refactored the LSM hook return values and
> added BPF return value checks.
>
> [1] used two methods to refactor hook return values:
>
> - converting positive return value to negative error code
>
> - adding additional output parameter to store odd return values
>
> Based on discussion in [1], only two hooks refactored with the
> second method may be acceptable. Since the second method requires
> extra work on BPF side to ensure that the output parameter is
> set properly, the extra work does not seem worthwhile for just
> two hooks. So this series includes only the two patches refactored
> with the first method.
>
> Changes to [1]:
> - Drop unnecessary patches
> - Rebase
> - Remove redundant comments in the inode_copy_up_xattr patch
>
> [1] https://lore.kernel.org/bpf/20240711111908.3817636-1-xukuohai@huaweicloud.com
>     https://lore.kernel.org/bpf/20240711113828.3818398-1-xukuohai@huaweicloud.com
>
> Xu Kuohai (2):
>   lsm: Refactor return value of LSM hook vm_enough_memory
>   lsm: Refactor return value of LSM hook inode_copy_up_xattr

For the series:
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>

>
>  fs/overlayfs/copy_up.c            |  6 +++---
>  include/linux/lsm_hook_defs.h     |  2 +-
>  include/linux/security.h          |  2 +-
>  security/commoncap.c              | 11 +++--------
>  security/integrity/evm/evm_main.c |  2 +-
>  security/security.c               | 22 ++++++++--------------
>  security/selinux/hooks.c          | 19 ++++++-------------
>  security/smack/smack_lsm.c        |  6 +++---
>  8 files changed, 26 insertions(+), 44 deletions(-)
>