[PATCH v8 2/8] auditsc: Replace memcpy() with strscpy()

[Justin Stitt]

Hi,

On Wed, Aug 28, 2024 at 11:03:15AM GMT, Yafang Shao wrote:
> Using strscpy() 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>
> Acked-by: 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(-)
> 
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 6f0d6fb6523f..e4ef5e57dde9 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);
> +	strscpy(context->target_comm, t->comm);
>  }
>  
>  /**
> @@ -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);
> +		strscpy(ctx->target_comm, t->comm);
>  		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);
> +	strscpy(axp->target_comm[axp->pid_count], t->comm);
>  	axp->pid_count++;
>  
>  	return 0;
> -- 
> 2.43.5
> 

Good usage of two-argument strscpy(). This helps towards [1].

Reviewed-by: Justin Stitt <justinstitt at google.com>

[1]: https://github.com/KSPP/linux/issues/90

Thanks
Justin