Re: [RFC PATCH 3/4] smack: differentiate between subjective and objective task credentials

With the split of the security_task_getsecid() into subjective and objective variants it's time to update Smack to ensure it is using the correct task creds. Signed-off-by: Paul Moore <paul(a)paul-moore.com&gt;

--- security/smack/smack.h | 18 +++++++++++++++++- security/smack/smack_lsm.c | 40 +++++++++++++++++++++++++++------------- 2 files changed, 44 insertions(+), 14 deletions(-) diff --git a/security/smack/smack.h b/security/smack/smack.h index a9768b12716bf..08f9cb80655ce 100644 --- a/security/smack/smack.h +++ b/security/smack/smack.h @@ -383,7 +383,23 @@ static inline struct smack_known *smk_of_task(const struct task_smack *tsp) return tsp->smk_task; } -static inline struct smack_known *smk_of_task_struct( +static inline struct smack_known *smk_of_task_struct_subj( + const struct task_struct *t) +{ + struct smack_known *skp; + const struct cred *cred; + + rcu_read_lock(); + + cred = rcu_dereference(t->cred); + skp = smk_of_task(smack_cred(cred)); + + rcu_read_unlock(); + + return skp; +} + +static inline struct smack_known *smk_of_task_struct_obj( const struct task_struct *t) { struct smack_known *skp; diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 2bb354ef2c4a9..ea1a82742e8ba 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -159,7 +159,7 @@ static int smk_bu_current(char *note, struct smack_known *oskp, static int smk_bu_task(struct task_struct *otp, int mode, int rc) { struct task_smack *tsp = smack_cred(current_cred()); - struct smack_known *smk_task = smk_of_task_struct(otp); + struct smack_known *smk_task = smk_of_task_struct_obj(otp); char acc[SMK_NUM_ACCESS_TYPE + 1]; if (rc <= 0) @@ -479,7 +479,7 @@ static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode) { struct smack_known *skp; - skp = smk_of_task_struct(ctp); + skp = smk_of_task_struct_obj(ctp); return smk_ptrace_rule_check(current, skp, mode, __func__); } @@ -2031,7 +2031,7 @@ static int smk_curacc_on_task(struct task_struct *p, int access, const char *caller) { struct smk_audit_info ad; - struct smack_known *skp = smk_of_task_struct(p); + struct smack_known *skp = smk_of_task_struct_subj(p); int rc; smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK); @@ -2076,15 +2076,29 @@ static int smack_task_getsid(struct task_struct *p) } /** - * smack_task_getsecid - get the secid of the task - * @p: the object task + * smack_task_getsecid_subj - get the subjective secid of the task + * @p: the task * @secid: where to put the result * - * Sets the secid to contain a u32 version of the smack label. + * Sets the secid to contain a u32 version of the task's subjective smack label. + */ +static void smack_task_getsecid_subj(struct task_struct *p, u32 *secid) +{ + struct smack_known *skp = smk_of_task_struct_subj(p); + + *secid = skp->smk_secid; +} + +/** + * smack_task_getsecid_obj - get the objective secid of the task + * @p: the task + * @secid: where to put the result + * + * Sets the secid to contain a u32 version of the task's objective smack label. */ -static void smack_task_getsecid(struct task_struct *p, u32 *secid) +static void smack_task_getsecid_obj(struct task_struct *p, u32 *secid) { - struct smack_known *skp = smk_of_task_struct(p); + struct smack_known *skp = smk_of_task_struct_obj(p); *secid = skp->smk_secid; } @@ -2172,7 +2186,7 @@ static int smack_task_kill(struct task_struct *p, struct kernel_siginfo *info, { struct smk_audit_info ad; struct smack_known *skp; - struct smack_known *tkp = smk_of_task_struct(p); + struct smack_known *tkp = smk_of_task_struct_obj(p); int rc; if (!sig) @@ -2210,7 +2224,7 @@ static int smack_task_kill(struct task_struct *p, struct kernel_siginfo *info, static void smack_task_to_inode(struct task_struct *p, struct inode *inode) { struct inode_smack *isp = smack_inode(inode); - struct smack_known *skp = smk_of_task_struct(p); + struct smack_known *skp = smk_of_task_struct_obj(p); isp->smk_inode = skp; isp->smk_flags |= SMK_INODE_INSTANT; @@ -3481,7 +3495,7 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode) */ static int smack_getprocattr(struct task_struct *p, char *name, char **value) { - struct smack_known *skp = smk_of_task_struct(p); + struct smack_known *skp = smk_of_task_struct_subj(p); char *cp; int slen; @@ -4755,8 +4769,8 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(task_setpgid, smack_task_setpgid), LSM_HOOK_INIT(task_getpgid, smack_task_getpgid), LSM_HOOK_INIT(task_getsid, smack_task_getsid), - LSM_HOOK_INIT(task_getsecid_subj, smack_task_getsecid), - LSM_HOOK_INIT(task_getsecid_obj, smack_task_getsecid), + LSM_HOOK_INIT(task_getsecid_subj, smack_task_getsecid_subj), + LSM_HOOK_INIT(task_getsecid_obj, smack_task_getsecid_obj), LSM_HOOK_INIT(task_setnice, smack_task_setnice), LSM_HOOK_INIT(task_setioprio, smack_task_setioprio), LSM_HOOK_INIT(task_getioprio, smack_task_getioprio),