2022-07-21 17:30:31

by Frederick Lawler

Subject: [PATCH v3 2/4] bpf-lsm: Make bpf_lsm_userns_create() sleepable

Users may want to audit calls to security_create_user_ns() and access
user space memory. Also create_user_ns() runs without
pagefault_disabled(). Therefore, make bpf_lsm_userns_create() sleepable
for mandatory access control policies.

Signed-off-by: Frederick Lawler <[email protected]>

---
Changes since v2:
- Rename create_user_ns hook to userns_create
Changes since v1:
- None
---
kernel/bpf/bpf_lsm.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/kernel/bpf/bpf_lsm.c b/kernel/bpf/bpf_lsm.c
index c1351df9f7ee..4593437809cc 100644
--- a/kernel/bpf/bpf_lsm.c
+++ b/kernel/bpf/bpf_lsm.c
@@ -250,6 +250,7 @@ BTF_ID(func, bpf_lsm_task_getsecid_obj)
BTF_ID(func, bpf_lsm_task_prctl)
BTF_ID(func, bpf_lsm_task_setscheduler)
BTF_ID(func, bpf_lsm_task_to_inode)
+BTF_ID(func, bpf_lsm_userns_create)
BTF_SET_END(sleepable_lsm_hooks)

bool bpf_lsm_is_sleepable_hook(u32 btf_id)
--
2.30.2

2022-07-22 08:31:12

by Christian Brauner

Subject: Re: [PATCH v3 2/4] bpf-lsm: Make bpf_lsm_userns_create() sleepable

On Thu, Jul 21, 2022 at 12:28:06PM -0500, Frederick Lawler wrote:
> Users may want to audit calls to security_create_user_ns() and access
> user space memory. Also create_user_ns() runs without
> pagefault_disabled(). Therefore, make bpf_lsm_userns_create() sleepable
> for mandatory access control policies.
>
> Signed-off-by: Frederick Lawler <[email protected]>
>
> ---

Seems reasonable,
Acked-by: Christian Brauner (Microsoft) <[email protected]>