[PATCH 3/6] auditsc: Replace memcpy() with __get_task_comm()

[Paul Moore]

On Sat, Jun 1, 2024 at 10:38 PM Yafang Shao <laoar.shao at gmail.com> wrote:
>
> Using __get_task_comm() to read the task comm ensures that the name is
> always NUL-terminated, regardless of the source string. This approach also
> facilitates future extensions to the task comm.
>
> Signed-off-by: Yafang Shao <laoar.shao at gmail.com>
> Cc: Paul Moore <paul at paul-moore.com>
> Cc: Eric Paris <eparis at redhat.com>
> ---
>  kernel/auditsc.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)

Assuming you've sorted out all the problems identified earlier in the
patchset and __get_task_comm() no longer takes task_lock() this should
be okay from an audit perspective.

Acked-by: Paul Moore <paul at paul-moore.com>

> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 6f0d6fb6523f..0459a141dc86 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -2730,7 +2730,7 @@ void __audit_ptrace(struct task_struct *t)
>         context->target_uid = task_uid(t);
>         context->target_sessionid = audit_get_sessionid(t);
>         security_task_getsecid_obj(t, &context->target_sid);
> -       memcpy(context->target_comm, t->comm, TASK_COMM_LEN);
> +       __get_task_comm(context->target_comm, TASK_COMM_LEN, t);
>  }
>
>  /**
> @@ -2757,7 +2757,7 @@ int audit_signal_info_syscall(struct task_struct *t)
>                 ctx->target_uid = t_uid;
>                 ctx->target_sessionid = audit_get_sessionid(t);
>                 security_task_getsecid_obj(t, &ctx->target_sid);
> -               memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN);
> +               __get_task_comm(ctx->target_comm, TASK_COMM_LEN, t);
>                 return 0;
>         }
>
> @@ -2778,7 +2778,7 @@ int audit_signal_info_syscall(struct task_struct *t)
>         axp->target_uid[axp->pid_count] = t_uid;
>         axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t);
>         security_task_getsecid_obj(t, &axp->target_sid[axp->pid_count]);
> -       memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN);
> +       __get_task_comm(axp->target_comm[axp->pid_count], TASK_COMM_LEN, t);
>         axp->pid_count++;
>
>         return 0;
> --
> 2.39.1

-- 
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