UBUNTU: SAUCE: LSM: Use lsmblob in security_cred_getsecid

Change the security_cred_getsecid() interface to fill in a
lsmblob instead of a u32 secid. The associated data elements
in the audit sub-system are changed from a secid to a lsmblob
to accommodate multiple possible LSM audit users.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
cc: linux-integrity@vger.kernel.org
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>

diff --git a/include/linux/security.h b/include/linux/security.h
index 3e018fa8cf684a9446a2acbc6bbdcbd50d379d52..55e9d8054f73bcbddc6556484c71e1d236bc731f 100644 (file)
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -478,7 +478,7 @@ int security_cred_alloc_blank(struct cred *cred, gfp_t gfp);
 void security_cred_free(struct cred *cred);
 int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp);
 void security_transfer_creds(struct cred *new, const struct cred *old);
-void security_cred_getsecid(const struct cred *c, u32 *secid);
+void security_cred_getsecid(const struct cred *c, struct lsmblob *blob);
 int security_kernel_act_as(struct cred *new, struct lsmblob *blob);
 int security_kernel_create_files_as(struct cred *new, struct inode *inode);
 int security_kernel_module_request(char *kmod_name);

diff --git a/kernel/audit.c b/kernel/audit.c
index d92c7b894183a6f72e719d0e2629bdf8c906061e..f44ba7a5ed9551c4e5c5905cf11b65196d6010e6 100644 (file)
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -125,7 +125,7 @@ static u32  audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME;
 /* The identity of the user shutting down the audit system. */
 static kuid_t          audit_sig_uid = INVALID_UID;
 static pid_t           audit_sig_pid = -1;
-static u32             audit_sig_sid;
+struct lsmblob audit_sig_lsm;
 
 /* Records can be lost in several ways:
    0) [suppressed in audit_alloc]
@@ -1441,29 +1441,21 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
        }
        case AUDIT_SIGNAL_INFO:
                len = 0;
-               if (audit_sig_sid) {
-                       struct lsmblob blob;
-
-                       /*
-                        * lsmblob_init sets all values in the lsmblob
-                        * to audit_sig_sid. This is temporary until
-                        * audit_sig_sid is converted to a lsmblob, which
-                        * happens later in this patch set.
-                        */
-                       lsmblob_init(&blob, audit_sig_sid);
-                       err = security_secid_to_secctx(&blob, &ctx, &len);
+               if (lsmblob_is_set(&audit_sig_lsm)) {
+                       err = security_secid_to_secctx(&audit_sig_lsm, &ctx,
+                                                      &len);
                        if (err)
                                return err;
                }
                sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
                if (!sig_data) {
-                       if (audit_sig_sid)
+                       if (lsmblob_is_set(&audit_sig_lsm))
                                security_release_secctx(ctx, len);
                        return -ENOMEM;
                }
                sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
                sig_data->pid = audit_sig_pid;
-               if (audit_sig_sid) {
+               if (lsmblob_is_set(&audit_sig_lsm)) {
                        memcpy(sig_data->ctx, ctx, len);
                        security_release_secctx(ctx, len);
                }
@@ -2352,7 +2344,6 @@ out:
 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 ||
@@ -2363,9 +2354,7 @@ int audit_signal_info(int sig, struct task_struct *t)
                        audit_sig_uid = auid;
                else
                        audit_sig_uid = uid;
-               security_task_getsecid_subj(current, &blob);
-               /* scaffolding until audit_sig_sid is converted */
-               audit_sig_sid = blob.secid[0];
+               security_task_getsecid_subj(current, &audit_sig_lsm);
        }
 
        return audit_signal_info_syscall(t);

diff --git a/kernel/audit.h b/kernel/audit.h
index d6a2c899a8dbfd38d70d9a96fcfdeaf79f14ba86..68ba39f8b68b1c5280bc8b90cd59efefcbd3b6c3 100644 (file)
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -12,6 +12,7 @@
 #include <linux/fs.h>
 #include <linux/audit.h>
 #include <linux/skbuff.h>
+#include <linux/security.h>
 #include <uapi/linux/mqueue.h>
 #include <linux/tty.h>
 
@@ -137,7 +138,7 @@ struct audit_context {
        kuid_t              target_auid;
        kuid_t              target_uid;
        unsigned int        target_sessionid;
-       u32                 target_sid;
+       struct lsmblob      target_lsm;
        char                target_comm[TASK_COMM_LEN];
 
        struct audit_tree_refs *trees, *first_trees;
@@ -330,6 +331,8 @@ static inline int audit_signal_info_syscall(struct task_struct *t)
 
 extern char *audit_unpack_string(void **bufp, size_t *remain, size_t len);
 
+extern struct lsmblob audit_sig_lsm;
+
 extern int audit_filter(int msgtype, unsigned int listtype);
 
 extern void audit_ctl_lock(void);

diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 7db0dd93d3e12c1401fff00e1f49dec482a78e8d..34714673cd64e6847807acd28f6b3ddd2191d1bc 100644 (file)
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -111,7 +111,7 @@ struct audit_aux_data_pids {
        kuid_t                  target_auid[AUDIT_AUX_PIDS];
        kuid_t                  target_uid[AUDIT_AUX_PIDS];
        unsigned int            target_sessionid[AUDIT_AUX_PIDS];
-       u32                     target_sid[AUDIT_AUX_PIDS];
+       struct lsmblob          target_lsm[AUDIT_AUX_PIDS];
        char                    target_comm[AUDIT_AUX_PIDS][TASK_COMM_LEN];
        int                     pid_count;
 };
@@ -998,14 +998,14 @@ static inline void audit_free_context(struct audit_context *context)
 }
 
 static int audit_log_pid_context(struct audit_context *context, pid_t pid,
-                                kuid_t auid, kuid_t uid, unsigned int sessionid,
-                                u32 sid, char *comm)
+                                kuid_t auid, kuid_t uid,
+                                unsigned int sessionid,
+                                struct lsmblob *blob, char *comm)
 {
        struct audit_buffer *ab;
        char *ctx = NULL;
        u32 len;
        int rc = 0;
-       struct lsmblob blob;
 
        ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
        if (!ab)
@@ -1014,9 +1014,8 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
        audit_log_format(ab, "opid=%d oauid=%d ouid=%d oses=%d", pid,
                         from_kuid(&init_user_ns, auid),
                         from_kuid(&init_user_ns, uid), sessionid);
-       if (sid) {
-               lsmblob_init(&blob, sid);
-               if (security_secid_to_secctx(&blob, &ctx, &len)) {
+       if (lsmblob_is_set(blob)) {
+               if (security_secid_to_secctx(blob, &ctx, &len)) {
                        audit_log_format(ab, " obj=(none)");
                        rc = 1;
                } else {
@@ -1591,7 +1590,7 @@ static void audit_log_exit(void)
                                                  axs->target_auid[i],
                                                  axs->target_uid[i],
                                                  axs->target_sessionid[i],
-                                                 axs->target_sid[i],
+                                                 &axs->target_lsm[i],
                                                  axs->target_comm[i]))
                                call_panic = 1;
        }
@@ -1600,7 +1599,7 @@ static void audit_log_exit(void)
            audit_log_pid_context(context, context->target_pid,
                                  context->target_auid, context->target_uid,
                                  context->target_sessionid,
-                                 context->target_sid, context->target_comm))
+                                 &context->target_lsm, context->target_comm))
                        call_panic = 1;
 
        if (context->pwd.dentry && context->pwd.mnt) {
@@ -1776,7 +1775,7 @@ void __audit_syscall_exit(int success, long return_code)
        context->aux = NULL;
        context->aux_pids = NULL;
        context->target_pid = 0;
-       context->target_sid = 0;
+       lsmblob_init(&context->target_lsm, 0);
        context->sockaddr_len = 0;
        context->type = 0;
        context->fds[0] = -1;
@@ -2434,15 +2433,12 @@ 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, &blob);
-       /* scaffolding - until target_sid is converted */
-       context->target_sid = blob.secid[0];
+       security_task_getsecid_obj(t, &context->target_lsm);
        memcpy(context->target_comm, t->comm, TASK_COMM_LEN);
 }
 
@@ -2458,7 +2454,6 @@ 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;
@@ -2470,9 +2465,7 @@ 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, &blob);
-               /* scaffolding until target_sid is converted */
-               ctx->target_sid = blob.secid[0];
+               security_task_getsecid_obj(t, &ctx->target_lsm);
                memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN);
                return 0;
        }
@@ -2493,9 +2486,7 @@ 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, &blob);
-       /* scaffolding until target_sid is converted */
-       axp->target_sid[axp->pid_count] = blob.secid[0];
+       security_task_getsecid_obj(t, &axp->target_lsm[axp->pid_count]);
        memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN);
        axp->pid_count++;
 

diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 3e4566dc43f2f26bb9f045104eb2e40068d35822..686297cc9c66815eb4cd80d6ce3c545d84c163ae 100644 (file)
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -487,7 +487,6 @@ int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot)
 int ima_bprm_check(struct linux_binprm *bprm)
 {
        int ret;
-       u32 secid;
        struct lsmblob blob;
 
        security_task_getsecid_subj(current, &blob);
@@ -497,9 +496,10 @@ int ima_bprm_check(struct linux_binprm *bprm)
        if (ret)
                return ret;
 
-       security_cred_getsecid(bprm->cred, &secid);
-       return process_measurement(bprm->file, bprm->cred, secid, NULL, 0,
-                                  MAY_EXEC, CREDS_CHECK);
+       security_cred_getsecid(bprm->cred, &blob);
+       /* scaffolding until process_measurement changes */
+       return process_measurement(bprm->file, bprm->cred, blob.secid[0],
+                                  NULL, 0, MAY_EXEC, CREDS_CHECK);
 }
 
 /**

diff --git a/security/security.c b/security/security.c
index 6ab33da136fa536f55f9467dfde264762a7dabd8..f2f8f6dda8c54b9962608fc17cd1e734638fd173 100644 (file)
--- a/security/security.c
+++ b/security/security.c
@@ -1756,10 +1756,16 @@ void security_transfer_creds(struct cred *new, const struct cred *old)
        call_void_hook(cred_transfer, new, old);
 }
 
-void security_cred_getsecid(const struct cred *c, u32 *secid)
+void security_cred_getsecid(const struct cred *c, struct lsmblob *blob)
 {
-       *secid = 0;
-       call_void_hook(cred_getsecid, c, secid);
+       struct security_hook_list *hp;
+
+       lsmblob_init(blob, 0);
+       hlist_for_each_entry(hp, &security_hook_heads.cred_getsecid, list) {
+               if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+                       continue;
+               hp->hook.cred_getsecid(c, &blob->secid[hp->lsmid->slot]);
+       }
 }
 EXPORT_SYMBOL(security_cred_getsecid);