[PATCH v4 17/23] LSM: Use lsmcontext in security_secid_to_secctx

[Casey Schaufler]

On 6/26/2019 8:53 PM, Kees Cook wrote:
> On Wed, Jun 26, 2019 at 12:22:28PM -0700, Casey Schaufler wrote:
>> Replace the (secctx,seclen) pointer pair with a single
>> lsmcontext pointer to allow return of the LSM identifier
>> along with the context and context length. This allows
>> security_release_secctx() to know how to release the
>> context. Callers have been modified to use or save the
>> returned data from the new structure.
>>
>> Signed-off-by: Casey Schaufler <casey at schaufler-ca.com>
>> ---
>>  drivers/android/binder.c                | 24 ++++++---------
>>  include/linux/security.h                |  4 +--
>>  include/net/scm.h                       |  9 ++----
>>  kernel/audit.c                          | 29 +++++++-----------
>>  kernel/auditsc.c                        | 31 +++++++------------
>>  net/ipv4/ip_sockglue.c                  |  7 ++---
>>  net/netfilter/nf_conntrack_netlink.c    | 14 +++++----
>>  net/netfilter/nf_conntrack_standalone.c |  7 ++---
>>  net/netfilter/nfnetlink_queue.c         |  5 +++-
>>  net/netlabel/netlabel_unlabeled.c       | 40 ++++++++-----------------
>>  net/netlabel/netlabel_user.c            |  7 ++---
>>  security/security.c                     |  9 ++++--
>>  12 files changed, 72 insertions(+), 114 deletions(-)
>>
>> diff --git a/drivers/android/binder.c b/drivers/android/binder.c
>> index 89e574be34cc..5d417a7b9bb3 100644
>> --- a/drivers/android/binder.c
>> +++ b/drivers/android/binder.c
>> @@ -2874,9 +2874,7 @@ static void binder_transaction(struct binder_proc *proc,
>>  	binder_size_t last_fixup_min_off = 0;
>>  	struct binder_context *context = proc->context;
>>  	int t_debug_id = atomic_inc_return(&binder_last_id);
>> -	char *secctx = NULL;
>> -	u32 secctx_sz = 0;
>> -	struct lsmcontext scaff; /* scaffolding */
>> +	struct lsmcontext lsmctx;
> As James found, this needs to be zero initialized:
>
> struct lsmcontext lsmctx = { };

Thanks! I'll incorporate this in v5. It's great to
have y'all checking it out.
??