Re: [PATCH] libsemanage: remove lock files

[Alan Jenkins <alan.christopher.jenkins@xxxxxxxxx>]

On 20/04/17 15:38, Guido Trentalancia wrote:
> Remove semanage read and transaction lock files upon releasing
> them.

What prevents this sequence?

A release lock
 B acquire lock
A unlink lock file
  C create lock file
  C acquire lock

> Signed-off-by: Guido Trentalancia <guido-D1bseh+SzQhuxeB9wqlrNw@xxxxxxxxxxxxxxxx>
> ---
>   src/semanage_store.c |    2 ++
>   1 file changed, 2 insertions(+)
>
> diff -pruN a/src/semanage_store.c b/src/semanage_store.c
> --- a/src/semanage_store.c	2016-10-14 17:31:26.000000000 +0200
> +++ b/src/semanage_store.c	2017-04-03 09:32:24.093627962 +0200
> @@ -1904,6 +1904,7 @@ void semanage_release_trans_lock(semanag
>   		close(sh->u.direct.translock_file_fd);
>   		sh->u.direct.translock_file_fd = -1;
>   	}
> +	unlink(semanage_files[SEMANAGE_TRANS_LOCK]);
>   	errno = errsv;
>   }
>   
> @@ -1917,6 +1918,7 @@ void semanage_release_active_lock(semana
>   		close(sh->u.direct.activelock_file_fd);
>   		sh->u.direct.activelock_file_fd = -1;
>   	}
> +	unlink(semanage_files[SEMANAGE_READ_LOCK]);
>   	errno = errsv;
>   }