[REVIEW][PATCH 13/11] ipc/smack: Tidy up from the change in type of the ipc security hooks
Casey Schaufler
casey at schaufler-ca.com
Sun Mar 25 00:05:01 UTC 2018
On 3/23/2018 10:42 PM, Eric W. Biederman wrote:
> Rename the variables shp, sma, msq to isp. As that is how the code already
> refers to those variables.
Thanks. It's important to keep the code readable.
> Collapse smack_of_shm, smack_of_sem, and smack_of_msq into smack_of_ipc,
> as the three functions had become completely identical.
Thanks. Completely reasonable and correct.
> Collapse smack_shm_alloc_security, smack_sem_alloc_security and
> smack_msg_queue_alloc_security into smack_ipc_alloc_security as the
> three functions had become identical.
>
> Collapse smack_shm_free_security, smack_sem_free_security and
> smack_msg_queue_free_security into smack_ipc_free_security as the three
> functions had become identical.
This is reasonable but unprecedented. Nowhere else is the
same function used to supply multiple LSM hooks. Does anyone
out there see a reason not to do this?
> Requested-by: Casey Schaufler <casey at schaufler-ca.com>
> Signed-off-by: "Eric W. Biederman" <ebiederm at xmission.com>
> ---
> security/smack/smack_lsm.c | 197 +++++++++++++--------------------------------
> 1 file changed, 58 insertions(+), 139 deletions(-)
>
> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
> index d960c2ea8d79..0735b8db158b 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -2945,25 +2945,24 @@ static void smack_msg_msg_free_security(struct msg_msg *msg)
> }
>
> /**
> - * smack_of_shm - the smack pointer for the shm
> - * @shp: the object
> + * smack_of_ipc - the smack pointer for the ipc
> + * @isp: the object
> *
> * Returns a pointer to the smack value
> */
> -static struct smack_known *smack_of_shm(struct kern_ipc_perm *shp)
> +static struct smack_known *smack_of_ipc(struct kern_ipc_perm *isp)
> {
> - return (struct smack_known *)shp->security;
> + return (struct smack_known *)isp->security;
> }
>
> /**
> - * smack_shm_alloc_security - Set the security blob for shm
> - * @shp: the object
> + * smack_ipc_alloc_security - Set the security blob for ipc
> + * @isp: the object
> *
> * Returns 0
> */
> -static int smack_shm_alloc_security(struct kern_ipc_perm *shp)
> +static int smack_ipc_alloc_security(struct kern_ipc_perm *isp)
> {
> - struct kern_ipc_perm *isp = shp;
> struct smack_known *skp = smk_of_current();
>
> isp->security = skp;
> @@ -2971,34 +2970,32 @@ static int smack_shm_alloc_security(struct kern_ipc_perm *shp)
> }
>
> /**
> - * smack_shm_free_security - Clear the security blob for shm
> - * @shp: the object
> + * smack_ipc_free_security - Clear the security blob for ipc
> + * @isp: the object
> *
> * Clears the blob pointer
> */
> -static void smack_shm_free_security(struct kern_ipc_perm *shp)
> +static void smack_ipc_free_security(struct kern_ipc_perm *isp)
> {
> - struct kern_ipc_perm *isp = shp;
> -
> isp->security = NULL;
> }
>
> /**
> * smk_curacc_shm : check if current has access on shm
> - * @shp : the object
> + * @isp : the object
> * @access : access requested
> *
> * Returns 0 if current has the requested access, error code otherwise
> */
> -static int smk_curacc_shm(struct kern_ipc_perm *shp, int access)
> +static int smk_curacc_shm(struct kern_ipc_perm *isp, int access)
> {
> - struct smack_known *ssp = smack_of_shm(shp);
> + struct smack_known *ssp = smack_of_ipc(isp);
> struct smk_audit_info ad;
> int rc;
>
> #ifdef CONFIG_AUDIT
> smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
> - ad.a.u.ipc_id = shp->id;
> + ad.a.u.ipc_id = isp->id;
> #endif
> rc = smk_curacc(ssp, access, &ad);
> rc = smk_bu_current("shm", ssp, access, rc);
> @@ -3007,27 +3004,27 @@ static int smk_curacc_shm(struct kern_ipc_perm *shp, int access)
>
> /**
> * smack_shm_associate - Smack access check for shm
> - * @shp: the object
> + * @isp: the object
> * @shmflg: access requested
> *
> * Returns 0 if current has the requested access, error code otherwise
> */
> -static int smack_shm_associate(struct kern_ipc_perm *shp, int shmflg)
> +static int smack_shm_associate(struct kern_ipc_perm *isp, int shmflg)
> {
> int may;
>
> may = smack_flags_to_may(shmflg);
> - return smk_curacc_shm(shp, may);
> + return smk_curacc_shm(isp, may);
> }
>
> /**
> * smack_shm_shmctl - Smack access check for shm
> - * @shp: the object
> + * @isp: the object
> * @cmd: what it wants to do
> *
> * Returns 0 if current has the requested access, error code otherwise
> */
> -static int smack_shm_shmctl(struct kern_ipc_perm *shp, int cmd)
> +static int smack_shm_shmctl(struct kern_ipc_perm *isp, int cmd)
> {
> int may;
>
> @@ -3051,81 +3048,42 @@ static int smack_shm_shmctl(struct kern_ipc_perm *shp, int cmd)
> default:
> return -EINVAL;
> }
> - return smk_curacc_shm(shp, may);
> + return smk_curacc_shm(isp, may);
> }
>
> /**
> * smack_shm_shmat - Smack access for shmat
> - * @shp: the object
> + * @isp: the object
> * @shmaddr: unused
> * @shmflg: access requested
> *
> * Returns 0 if current has the requested access, error code otherwise
> */
> -static int smack_shm_shmat(struct kern_ipc_perm *shp, char __user *shmaddr,
> +static int smack_shm_shmat(struct kern_ipc_perm *ipc, char __user *shmaddr,
> int shmflg)
> {
> int may;
>
> may = smack_flags_to_may(shmflg);
> - return smk_curacc_shm(shp, may);
> -}
> -
> -/**
> - * smack_of_sem - the smack pointer for the sem
> - * @sma: the object
> - *
> - * Returns a pointer to the smack value
> - */
> -static struct smack_known *smack_of_sem(struct kern_ipc_perm *sma)
> -{
> - return (struct smack_known *)sma->security;
> -}
> -
> -/**
> - * smack_sem_alloc_security - Set the security blob for sem
> - * @sma: the object
> - *
> - * Returns 0
> - */
> -static int smack_sem_alloc_security(struct kern_ipc_perm *sma)
> -{
> - struct kern_ipc_perm *isp = sma;
> - struct smack_known *skp = smk_of_current();
> -
> - isp->security = skp;
> - return 0;
> -}
> -
> -/**
> - * smack_sem_free_security - Clear the security blob for sem
> - * @sma: the object
> - *
> - * Clears the blob pointer
> - */
> -static void smack_sem_free_security(struct kern_ipc_perm *sma)
> -{
> - struct kern_ipc_perm *isp = sma;
> -
> - isp->security = NULL;
> + return smk_curacc_shm(ipc, may);
> }
>
> /**
> * smk_curacc_sem : check if current has access on sem
> - * @sma : the object
> + * @isp : the object
> * @access : access requested
> *
> * Returns 0 if current has the requested access, error code otherwise
> */
> -static int smk_curacc_sem(struct kern_ipc_perm *sma, int access)
> +static int smk_curacc_sem(struct kern_ipc_perm *isp, int access)
> {
> - struct smack_known *ssp = smack_of_sem(sma);
> + struct smack_known *ssp = smack_of_ipc(isp);
> struct smk_audit_info ad;
> int rc;
>
> #ifdef CONFIG_AUDIT
> smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
> - ad.a.u.ipc_id = sma->id;
> + ad.a.u.ipc_id = isp->id;
> #endif
> rc = smk_curacc(ssp, access, &ad);
> rc = smk_bu_current("sem", ssp, access, rc);
> @@ -3134,27 +3092,27 @@ static int smk_curacc_sem(struct kern_ipc_perm *sma, int access)
>
> /**
> * smack_sem_associate - Smack access check for sem
> - * @sma: the object
> + * @isp: the object
> * @semflg: access requested
> *
> * Returns 0 if current has the requested access, error code otherwise
> */
> -static int smack_sem_associate(struct kern_ipc_perm *sma, int semflg)
> +static int smack_sem_associate(struct kern_ipc_perm *isp, int semflg)
> {
> int may;
>
> may = smack_flags_to_may(semflg);
> - return smk_curacc_sem(sma, may);
> + return smk_curacc_sem(isp, may);
> }
>
> /**
> * smack_sem_shmctl - Smack access check for sem
> - * @sma: the object
> + * @isp: the object
> * @cmd: what it wants to do
> *
> * Returns 0 if current has the requested access, error code otherwise
> */
> -static int smack_sem_semctl(struct kern_ipc_perm *sma, int cmd)
> +static int smack_sem_semctl(struct kern_ipc_perm *isp, int cmd)
> {
> int may;
>
> @@ -3184,12 +3142,12 @@ static int smack_sem_semctl(struct kern_ipc_perm *sma, int cmd)
> return -EINVAL;
> }
>
> - return smk_curacc_sem(sma, may);
> + return smk_curacc_sem(isp, may);
> }
>
> /**
> * smack_sem_semop - Smack checks of semaphore operations
> - * @sma: the object
> + * @isp: the object
> * @sops: unused
> * @nsops: unused
> * @alter: unused
> @@ -3198,67 +3156,28 @@ static int smack_sem_semctl(struct kern_ipc_perm *sma, int cmd)
> *
> * Returns 0 if access is allowed, error code otherwise
> */
> -static int smack_sem_semop(struct kern_ipc_perm *sma, struct sembuf *sops,
> +static int smack_sem_semop(struct kern_ipc_perm *isp, struct sembuf *sops,
> unsigned nsops, int alter)
> {
> - return smk_curacc_sem(sma, MAY_READWRITE);
> -}
> -
> -/**
> - * smack_msg_alloc_security - Set the security blob for msg
> - * @msq: the object
> - *
> - * Returns 0
> - */
> -static int smack_msg_queue_alloc_security(struct kern_ipc_perm *msq)
> -{
> - struct kern_ipc_perm *kisp = msq;
> - struct smack_known *skp = smk_of_current();
> -
> - kisp->security = skp;
> - return 0;
> -}
> -
> -/**
> - * smack_msg_free_security - Clear the security blob for msg
> - * @msq: the object
> - *
> - * Clears the blob pointer
> - */
> -static void smack_msg_queue_free_security(struct kern_ipc_perm *msq)
> -{
> - struct kern_ipc_perm *kisp = msq;
> -
> - kisp->security = NULL;
> -}
> -
> -/**
> - * smack_of_msq - the smack pointer for the msq
> - * @msq: the object
> - *
> - * Returns a pointer to the smack label entry
> - */
> -static struct smack_known *smack_of_msq(struct kern_ipc_perm *msq)
> -{
> - return (struct smack_known *)msq->security;
> + return smk_curacc_sem(isp, MAY_READWRITE);
> }
>
> /**
> * smk_curacc_msq : helper to check if current has access on msq
> - * @msq : the msq
> + * @isp : the msq
> * @access : access requested
> *
> * return 0 if current has access, error otherwise
> */
> -static int smk_curacc_msq(struct kern_ipc_perm *msq, int access)
> +static int smk_curacc_msq(struct kern_ipc_perm *isp, int access)
> {
> - struct smack_known *msp = smack_of_msq(msq);
> + struct smack_known *msp = smack_of_ipc(isp);
> struct smk_audit_info ad;
> int rc;
>
> #ifdef CONFIG_AUDIT
> smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
> - ad.a.u.ipc_id = msq->id;
> + ad.a.u.ipc_id = isp->id;
> #endif
> rc = smk_curacc(msp, access, &ad);
> rc = smk_bu_current("msq", msp, access, rc);
> @@ -3267,27 +3186,27 @@ static int smk_curacc_msq(struct kern_ipc_perm *msq, int access)
>
> /**
> * smack_msg_queue_associate - Smack access check for msg_queue
> - * @msq: the object
> + * @isp: the object
> * @msqflg: access requested
> *
> * Returns 0 if current has the requested access, error code otherwise
> */
> -static int smack_msg_queue_associate(struct kern_ipc_perm *msq, int msqflg)
> +static int smack_msg_queue_associate(struct kern_ipc_perm *isp, int msqflg)
> {
> int may;
>
> may = smack_flags_to_may(msqflg);
> - return smk_curacc_msq(msq, may);
> + return smk_curacc_msq(isp, may);
> }
>
> /**
> * smack_msg_queue_msgctl - Smack access check for msg_queue
> - * @msq: the object
> + * @isp: the object
> * @cmd: what it wants to do
> *
> * Returns 0 if current has the requested access, error code otherwise
> */
> -static int smack_msg_queue_msgctl(struct kern_ipc_perm *msq, int cmd)
> +static int smack_msg_queue_msgctl(struct kern_ipc_perm *isp, int cmd)
> {
> int may;
>
> @@ -3310,29 +3229,29 @@ static int smack_msg_queue_msgctl(struct kern_ipc_perm *msq, int cmd)
> return -EINVAL;
> }
>
> - return smk_curacc_msq(msq, may);
> + return smk_curacc_msq(isp, may);
> }
>
> /**
> * smack_msg_queue_msgsnd - Smack access check for msg_queue
> - * @msq: the object
> + * @isp: the object
> * @msg: unused
> * @msqflg: access requested
> *
> * Returns 0 if current has the requested access, error code otherwise
> */
> -static int smack_msg_queue_msgsnd(struct kern_ipc_perm *msq, struct msg_msg *msg,
> +static int smack_msg_queue_msgsnd(struct kern_ipc_perm *isp, struct msg_msg *msg,
> int msqflg)
> {
> int may;
>
> may = smack_flags_to_may(msqflg);
> - return smk_curacc_msq(msq, may);
> + return smk_curacc_msq(isp, may);
> }
>
> /**
> * smack_msg_queue_msgsnd - Smack access check for msg_queue
> - * @msq: the object
> + * @isp: the object
> * @msg: unused
> * @target: unused
> * @type: unused
> @@ -3340,10 +3259,10 @@ static int smack_msg_queue_msgsnd(struct kern_ipc_perm *msq, struct msg_msg *msg
> *
> * Returns 0 if current has read and write access, error code otherwise
> */
> -static int smack_msg_queue_msgrcv(struct kern_ipc_perm *msq, struct msg_msg *msg,
> +static int smack_msg_queue_msgrcv(struct kern_ipc_perm *isp, struct msg_msg *msg,
> struct task_struct *target, long type, int mode)
> {
> - return smk_curacc_msq(msq, MAY_READWRITE);
> + return smk_curacc_msq(isp, MAY_READWRITE);
> }
>
> /**
> @@ -4756,21 +4675,21 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
> LSM_HOOK_INIT(msg_msg_alloc_security, smack_msg_msg_alloc_security),
> LSM_HOOK_INIT(msg_msg_free_security, smack_msg_msg_free_security),
>
> - LSM_HOOK_INIT(msg_queue_alloc_security, smack_msg_queue_alloc_security),
> - LSM_HOOK_INIT(msg_queue_free_security, smack_msg_queue_free_security),
> + LSM_HOOK_INIT(msg_queue_alloc_security, smack_ipc_alloc_security),
> + LSM_HOOK_INIT(msg_queue_free_security, smack_ipc_free_security),
> LSM_HOOK_INIT(msg_queue_associate, smack_msg_queue_associate),
> LSM_HOOK_INIT(msg_queue_msgctl, smack_msg_queue_msgctl),
> LSM_HOOK_INIT(msg_queue_msgsnd, smack_msg_queue_msgsnd),
> LSM_HOOK_INIT(msg_queue_msgrcv, smack_msg_queue_msgrcv),
>
> - LSM_HOOK_INIT(shm_alloc_security, smack_shm_alloc_security),
> - LSM_HOOK_INIT(shm_free_security, smack_shm_free_security),
> + LSM_HOOK_INIT(shm_alloc_security, smack_ipc_alloc_security),
> + LSM_HOOK_INIT(shm_free_security, smack_ipc_free_security),
> LSM_HOOK_INIT(shm_associate, smack_shm_associate),
> LSM_HOOK_INIT(shm_shmctl, smack_shm_shmctl),
> LSM_HOOK_INIT(shm_shmat, smack_shm_shmat),
>
> - LSM_HOOK_INIT(sem_alloc_security, smack_sem_alloc_security),
> - LSM_HOOK_INIT(sem_free_security, smack_sem_free_security),
> + LSM_HOOK_INIT(sem_alloc_security, smack_ipc_alloc_security),
> + LSM_HOOK_INIT(sem_free_security, smack_ipc_free_security),
> LSM_HOOK_INIT(sem_associate, smack_sem_associate),
> LSM_HOOK_INIT(sem_semctl, smack_sem_semctl),
> LSM_HOOK_INIT(sem_semop, smack_sem_semop),
--
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