[PATCH v33 11/29] LSM: Use lsmblob in security_current_getsecid
From: Casey Schaufler <casey@schaufler-ca.com>
Date: 2022-03-10 23:52:14
Also in:
linux-integrity, lkml, netdev, selinux
Subsystem:
android drivers, audit subsystem, extended verification module (evm), integrity measurement architecture (ima), networking [general], networking [labeled] (netlabel, labeled ipsec, secmark), security subsystem, the rest · Maintainers:
Greg Kroah-Hartman, Arve Hjønnevåg, Todd Kjos, Christian Brauner, Carlos Llamas, Alice Ryhl, Paul Moore, Eric Paris, Mimi Zohar, Roberto Sassu, Dmitry Kasatkin, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, James Morris, "Serge E. Hallyn", Linus Torvalds
Change the security_current_getsecid_subj() and security_task_getsecid_obj() interfaces to fill in a lsmblob structure instead of a u32 secid in support of LSM stacking. Audit interfaces will need to collect all possible secids for possible reporting. Reviewed-by: Kees Cook <redacted> Reviewed-by: John Johansen <john.johansen@canonical.com> Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com> Acked-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Cc: linux-integrity@vger.kernel.org Cc: linux-audit@redhat.com Cc: netdev@vger.kernel.org --- drivers/android/binder.c | 6 +-- include/linux/security.h | 13 ++++--- kernel/audit.c | 16 +++----- kernel/auditfilter.c | 4 +- kernel/auditsc.c | 25 ++++++------ net/netlabel/netlabel_unlabeled.c | 5 ++- net/netlabel/netlabel_user.h | 6 ++- security/integrity/ima/ima_appraise.c | 12 +++--- security/integrity/ima/ima_main.c | 55 +++++++++++++++------------ security/security.c | 25 +++++++++--- 10 files changed, 95 insertions(+), 72 deletions(-)
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 381a4fddd4a5..bae8440ffc73 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c@@ -2980,16 +2980,16 @@ static void binder_transaction(struct binder_proc *proc, t->priority = task_nice(current); if (target_node && target_node->txn_security_ctx) { - u32 secid; struct lsmblob blob; size_t added_size; + u32 secid; security_cred_getsecid(proc->cred, &secid); /* - * Later in this patch set security_task_getsecid() will + * Later in this patch set security_cred_getsecid() will * provide a lsmblob instead of a secid. lsmblob_init * is used to ensure that all the secids in the lsmblob - * get the value returned from security_task_getsecid(), + * get the value returned from security_cred_getsecid(), * which means that the one expected by * security_secid_to_secctx() will be set. */
diff --git a/include/linux/security.h b/include/linux/security.h
index 1814516509ec..5f20c0c68f67 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h@@ -502,8 +502,8 @@ int security_task_fix_setgid(struct cred *new, const struct cred *old, int security_task_setpgid(struct task_struct *p, pid_t pgid); int security_task_getpgid(struct task_struct *p); int security_task_getsid(struct task_struct *p); -void security_current_getsecid_subj(u32 *secid); -void security_task_getsecid_obj(struct task_struct *p, u32 *secid); +void security_current_getsecid_subj(struct lsmblob *blob); +void security_task_getsecid_obj(struct task_struct *p, struct lsmblob *blob); int security_task_setnice(struct task_struct *p, int nice); int security_task_setioprio(struct task_struct *p, int ioprio); int security_task_getioprio(struct task_struct *p);
@@ -1199,14 +1199,15 @@ static inline int security_task_getsid(struct task_struct *p) return 0; } -static inline void security_current_getsecid_subj(u32 *secid) +static inline void security_current_getsecid_subj(struct lsmblob *blob) { - *secid = 0; + lsmblob_init(blob, 0); } -static inline void security_task_getsecid_obj(struct task_struct *p, u32 *secid) +static inline void security_task_getsecid_obj(struct task_struct *p, + struct lsmblob *blob) { - *secid = 0; + lsmblob_init(blob, 0); } static inline int security_task_setnice(struct task_struct *p, int nice)
diff --git a/kernel/audit.c b/kernel/audit.c
index 40d8cb824eae..17ac6e74b5bd 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c@@ -2154,19 +2154,12 @@ int audit_log_task_context(struct audit_buffer *ab) char *ctx = NULL; unsigned len; int error; - u32 sid; struct lsmblob blob; - security_current_getsecid_subj(&sid); - if (!sid) + security_current_getsecid_subj(&blob); + if (!lsmblob_is_set(&blob)) return 0; - /* - * lsmblob_init sets all values in the lsmblob to sid. - * This is temporary until security_task_getsecid is converted - * to use a lsmblob, which happens later in this patch set. - */ - lsmblob_init(&blob, sid); error = security_secid_to_secctx(&blob, &ctx, &len); if (error) {
@@ -2375,6 +2368,7 @@ int audit_set_loginuid(kuid_t loginuid) int audit_signal_info(int sig, struct task_struct *t) { kuid_t uid = current_uid(), auid; + struct lsmblob blob; if (auditd_test_task(t) && (sig == SIGTERM || sig == SIGHUP ||
@@ -2385,7 +2379,9 @@ int audit_signal_info(int sig, struct task_struct *t) audit_sig_uid = auid; else audit_sig_uid = uid; - security_current_getsecid_subj(&audit_sig_sid); + security_current_getsecid_subj(&blob); + /* scaffolding until audit_sig_sid is converted */ + audit_sig_sid = blob.secid[0]; } return audit_signal_info_syscall(t);
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index 15cd4fe35e9c..39ded5cb2429 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c@@ -1339,7 +1339,6 @@ int audit_filter(int msgtype, unsigned int listtype) struct audit_field *f = &e->rule.fields[i]; struct lsmblob blob; pid_t pid; - u32 sid; switch (f->type) { case AUDIT_PID:
@@ -1369,8 +1368,7 @@ int audit_filter(int msgtype, unsigned int listtype) case AUDIT_SUBJ_SEN: case AUDIT_SUBJ_CLR: if (f->lsm_str) { - security_current_getsecid_subj(&sid); - lsmblob_init(&blob, sid); + security_current_getsecid_subj(&blob); result = security_audit_rule_match( &blob, f->type, f->op, &f->lsm_rules);
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 598e0de45b04..2570bf5979e0 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c@@ -467,7 +467,6 @@ static int audit_filter_rules(struct task_struct *tsk, { const struct cred *cred; int i, need_sid = 1; - u32 sid; struct lsmblob blob; unsigned int sessionid;
@@ -676,17 +675,9 @@ static int audit_filter_rules(struct task_struct *tsk, * here even though it always refs * @current's creds */ - security_current_getsecid_subj(&sid); + security_current_getsecid_subj(&blob); need_sid = 0; } - /* - * lsmblob_init sets all values in the lsmblob - * to sid. This is temporary until - * security_task_getsecid() is converted to - * provide a lsmblob, which happens later in - * this patch set. - */ - lsmblob_init(&blob, sid); result = security_audit_rule_match(&blob, f->type, f->op, &f->lsm_rules);
@@ -2712,12 +2703,15 @@ int __audit_sockaddr(int len, void *a) void __audit_ptrace(struct task_struct *t) { struct audit_context *context = audit_context(); + struct lsmblob blob; context->target_pid = task_tgid_nr(t); context->target_auid = audit_get_loginuid(t); context->target_uid = task_uid(t); context->target_sessionid = audit_get_sessionid(t); - security_task_getsecid_obj(t, &context->target_sid); + security_task_getsecid_obj(t, &blob); + /* scaffolding - until target_sid is converted */ + context->target_sid = blob.secid[0]; memcpy(context->target_comm, t->comm, TASK_COMM_LEN); }
@@ -2733,6 +2727,7 @@ int audit_signal_info_syscall(struct task_struct *t) struct audit_aux_data_pids *axp; struct audit_context *ctx = audit_context(); kuid_t t_uid = task_uid(t); + struct lsmblob blob; if (!audit_signals || audit_dummy_context()) return 0;
@@ -2744,7 +2739,9 @@ int audit_signal_info_syscall(struct task_struct *t) ctx->target_auid = audit_get_loginuid(t); ctx->target_uid = t_uid; ctx->target_sessionid = audit_get_sessionid(t); - security_task_getsecid_obj(t, &ctx->target_sid); + security_task_getsecid_obj(t, &blob); + /* scaffolding until target_sid is converted */ + ctx->target_sid = blob.secid[0]; memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN); return 0; }
@@ -2765,7 +2762,9 @@ int audit_signal_info_syscall(struct task_struct *t) axp->target_auid[axp->pid_count] = audit_get_loginuid(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]); + security_task_getsecid_obj(t, &blob); + /* scaffolding until target_sid is converted */ + axp->target_sid[axp->pid_count] = blob.secid[0]; memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN); axp->pid_count++;
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index 0a99663e6edb..c86df6ead742 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c@@ -1562,11 +1562,14 @@ int __init netlbl_unlabel_defconf(void) int ret_val; struct netlbl_dom_map *entry; struct netlbl_audit audit_info; + struct lsmblob blob; /* Only the kernel is allowed to call this function and the only time * it is called is at bootup before the audit subsystem is reporting * messages so don't worry to much about these values. */ - security_current_getsecid_subj(&audit_info.secid); + security_current_getsecid_subj(&blob); + /* scaffolding until audit_info.secid is converted */ + audit_info.secid = blob.secid[0]; audit_info.loginuid = GLOBAL_ROOT_UID; audit_info.sessionid = 0;
diff --git a/net/netlabel/netlabel_user.h b/net/netlabel/netlabel_user.h
index d6c5b31eb4eb..3d5610ed5f0e 100644
--- a/net/netlabel/netlabel_user.h
+++ b/net/netlabel/netlabel_user.h@@ -32,7 +32,11 @@ */ static inline void netlbl_netlink_auditinfo(struct netlbl_audit *audit_info) { - security_current_getsecid_subj(&audit_info->secid); + struct lsmblob blob; + + security_current_getsecid_subj(&blob); + /* scaffolding until secid is converted */ + audit_info->secid = blob.secid[0]; audit_info->loginuid = audit_get_loginuid(current); audit_info->sessionid = audit_get_sessionid(current); }
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index 17232bbfb9f9..217d20c60e1d 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c@@ -71,15 +71,17 @@ bool is_ima_appraise_enabled(void) int ima_must_appraise(struct user_namespace *mnt_userns, struct inode *inode, int mask, enum ima_hooks func) { - u32 secid; + struct lsmblob blob; if (!ima_appraise) return 0; - security_current_getsecid_subj(&secid); - return ima_match_policy(mnt_userns, inode, current_cred(), secid, - func, mask, IMA_APPRAISE | IMA_HASH, NULL, - NULL, NULL, NULL); + security_current_getsecid_subj(&blob); + /* scaffolding the .secid[0] */ + return ima_match_policy(mnt_userns, inode, current_cred(), + blob.secid[0], func, mask, + IMA_APPRAISE | IMA_HASH, NULL, NULL, NULL, + NULL); } static int ima_fix_xattr(struct dentry *dentry,
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 8c6e4514d494..6abbaa97bbeb 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c@@ -405,12 +405,13 @@ static int process_measurement(struct file *file, const struct cred *cred, */ int ima_file_mmap(struct file *file, unsigned long prot) { - u32 secid; + struct lsmblob blob; if (file && (prot & PROT_EXEC)) { - security_current_getsecid_subj(&secid); - return process_measurement(file, current_cred(), secid, NULL, - 0, MAY_EXEC, MMAP_CHECK); + security_current_getsecid_subj(&blob); + /* scaffolding - until process_measurement changes */ + return process_measurement(file, current_cred(), blob.secid[0], + NULL, 0, MAY_EXEC, MMAP_CHECK); } return 0;
@@ -436,9 +437,9 @@ int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot) char *pathbuf = NULL; const char *pathname = NULL; struct inode *inode; + struct lsmblob blob; int result = 0; int action; - u32 secid; int pcr; /* Is mprotect making an mmap'ed file executable? */
@@ -446,11 +447,11 @@ int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot) !(prot & PROT_EXEC) || (vma->vm_flags & VM_EXEC)) return 0; - security_current_getsecid_subj(&secid); + security_current_getsecid_subj(&blob); inode = file_inode(vma->vm_file); action = ima_get_action(file_mnt_user_ns(vma->vm_file), inode, - current_cred(), secid, MAY_EXEC, MMAP_CHECK, - &pcr, &template, NULL, NULL); + current_cred(), blob.secid[0], MAY_EXEC, + MMAP_CHECK, &pcr, &template, NULL, NULL); /* Is the mmap'ed file in policy? */ if (!(action & (IMA_MEASURE | IMA_APPRAISE_SUBMASK)))
@@ -486,10 +487,12 @@ int ima_bprm_check(struct linux_binprm *bprm) { int ret; u32 secid; + struct lsmblob blob; - security_current_getsecid_subj(&secid); - ret = process_measurement(bprm->file, current_cred(), secid, NULL, 0, - MAY_EXEC, BPRM_CHECK); + security_current_getsecid_subj(&blob); + /* scaffolding until process_measurement changes */ + ret = process_measurement(bprm->file, current_cred(), blob.secid[0], + NULL, 0, MAY_EXEC, BPRM_CHECK); if (ret) return ret;
@@ -510,10 +513,11 @@ int ima_bprm_check(struct linux_binprm *bprm) */ int ima_file_check(struct file *file, int mask) { - u32 secid; + struct lsmblob blob; - security_current_getsecid_subj(&secid); - return process_measurement(file, current_cred(), secid, NULL, 0, + security_current_getsecid_subj(&blob); + /* scaffolding until process_measurement changes */ + return process_measurement(file, current_cred(), blob.secid[0], NULL, 0, mask & (MAY_READ | MAY_WRITE | MAY_EXEC | MAY_APPEND), FILE_CHECK); }
@@ -689,7 +693,7 @@ int ima_read_file(struct file *file, enum kernel_read_file_id read_id, bool contents) { enum ima_hooks func; - u32 secid; + struct lsmblob blob; /* * Do devices using pre-allocated memory run the risk of the
@@ -709,8 +713,9 @@ int ima_read_file(struct file *file, enum kernel_read_file_id read_id, /* Read entire file for all partial reads. */ func = read_idmap[read_id] ?: FILE_CHECK; - security_current_getsecid_subj(&secid); - return process_measurement(file, current_cred(), secid, NULL, + security_current_getsecid_subj(&blob); + /* scaffolding - until process_measurement changes */ + return process_measurement(file, current_cred(), blob.secid[0], NULL, 0, MAY_READ, func); }
@@ -739,7 +744,7 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size, enum kernel_read_file_id read_id) { enum ima_hooks func; - u32 secid; + struct lsmblob blob; /* permit signed certs */ if (!file && read_id == READING_X509_CERTIFICATE)
@@ -752,9 +757,10 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size, } func = read_idmap[read_id] ?: FILE_CHECK; - security_current_getsecid_subj(&secid); - return process_measurement(file, current_cred(), secid, buf, size, - MAY_READ, func); + security_current_getsecid_subj(&blob); + /* scaffolding - until process_measurement changes */ + return process_measurement(file, current_cred(), blob.secid[0], buf, + size, MAY_READ, func); } /**
@@ -882,7 +888,7 @@ int process_buffer_measurement(struct user_namespace *mnt_userns, int digest_hash_len = hash_digest_size[ima_hash_algo]; int violation = 0; int action = 0; - u32 secid; + struct lsmblob blob; if (digest && digest_len < digest_hash_len) return -EINVAL;
@@ -905,9 +911,10 @@ int process_buffer_measurement(struct user_namespace *mnt_userns, * buffer measurements. */ if (func) { - security_current_getsecid_subj(&secid); + security_current_getsecid_subj(&blob); + /* scaffolding */ action = ima_get_action(mnt_userns, inode, current_cred(), - secid, 0, func, &pcr, &template, + blob.secid[0], 0, func, &pcr, &template, func_data, NULL); if (!(action & IMA_MEASURE) && !digest) return -ENOENT;
diff --git a/security/security.c b/security/security.c
index 815200684bcf..e33fa677181d 100644
--- a/security/security.c
+++ b/security/security.c@@ -1909,17 +1909,30 @@ int security_task_getsid(struct task_struct *p) return call_int_hook(task_getsid, 0, p); } -void security_current_getsecid_subj(u32 *secid) +void security_current_getsecid_subj(struct lsmblob *blob) { - *secid = 0; - call_void_hook(current_getsecid_subj, secid); + struct security_hook_list *hp; + + lsmblob_init(blob, 0); + hlist_for_each_entry(hp, &security_hook_heads.current_getsecid_subj, + list) { + if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot)) + continue; + hp->hook.current_getsecid_subj(&blob->secid[hp->lsmid->slot]); + } } EXPORT_SYMBOL(security_current_getsecid_subj); -void security_task_getsecid_obj(struct task_struct *p, u32 *secid) +void security_task_getsecid_obj(struct task_struct *p, struct lsmblob *blob) { - *secid = 0; - call_void_hook(task_getsecid_obj, p, secid); + struct security_hook_list *hp; + + lsmblob_init(blob, 0); + hlist_for_each_entry(hp, &security_hook_heads.task_getsecid_obj, list) { + if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot)) + continue; + hp->hook.task_getsecid_obj(p, &blob->secid[hp->lsmid->slot]); + } } EXPORT_SYMBOL(security_task_getsecid_obj);
--
2.31.1