[PATCH v4 11/23] LSM: Use lsmblob in security_task_getsecid
Kees Cook
keescook at chromium.org
Wed Jun 26 23:08:29 UTC 2019
On Wed, Jun 26, 2019 at 12:22:22PM -0700, Casey Schaufler wrote:
> Change the security_task_getsecid() interface 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.
>
> Signed-off-by: Casey Schaufler <casey at schaufler-ca.com>
Reviewed-by: Kees Cook <keescook at chromium.org>
-Kees
> ---
> drivers/android/binder.c | 4 +---
> include/linux/security.h | 7 +++---
> kernel/audit.c | 6 ++---
> kernel/auditfilter.c | 4 +---
> kernel/auditsc.c | 22 ++++++++++++------
> net/netlabel/netlabel_unlabeled.c | 5 +++-
> net/netlabel/netlabel_user.h | 6 ++++-
> security/integrity/ima/ima_appraise.c | 4 +++-
> security/integrity/ima/ima_main.c | 33 +++++++++++++++------------
> security/security.c | 12 +++++++---
> 10 files changed, 63 insertions(+), 40 deletions(-)
>
> diff --git a/drivers/android/binder.c b/drivers/android/binder.c
> index 1962f6b8abd0..144ac4f1c24f 100644
> --- a/drivers/android/binder.c
> +++ b/drivers/android/binder.c
> @@ -3119,11 +3119,9 @@ 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;
>
> - security_task_getsecid(proc->tsk, &secid);
> - lsmblob_init(&blob, secid);
> + security_task_getsecid(proc->tsk, &blob);
> ret = security_secid_to_secctx(&blob, &secctx, &secctx_sz);
> if (ret) {
> return_error = BR_FAILED_REPLY;
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 41dc3053094e..cfd7cf4b0be9 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -400,7 +400,7 @@ int security_task_fix_setuid(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_task_getsecid(struct task_struct *p, u32 *secid);
> +void security_task_getsecid(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);
> @@ -1029,9 +1029,10 @@ static inline int security_task_getsid(struct task_struct *p)
> return 0;
> }
>
> -static inline void security_task_getsecid(struct task_struct *p, u32 *secid)
> +static inline void security_task_getsecid(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 d0338411d75d..a0205f3c23c7 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -2075,14 +2075,12 @@ int audit_log_task_context(struct audit_buffer *ab)
> char *ctx = NULL;
> unsigned len;
> int error;
> - u32 sid;
> struct lsmblob blob;
>
> - security_task_getsecid(current, &sid);
> - if (!sid)
> + security_task_getsecid(current, &blob);
> + if (!lsmblob_is_set(&blob))
> return 0;
>
> - lsmblob_init(&blob, sid);
> error = security_secid_to_secctx(&blob, &ctx, &len);
> if (error) {
> if (error != -EINVAL)
> diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
> index 8786b95b60bd..8f244c98bb57 100644
> --- a/kernel/auditfilter.c
> +++ b/kernel/auditfilter.c
> @@ -1323,7 +1323,6 @@ int audit_filter(int msgtype, unsigned int listtype)
> for (i = 0; i < e->rule.field_count; i++) {
> struct audit_field *f = &e->rule.fields[i];
> pid_t pid;
> - u32 sid;
> struct lsmblob blob;
>
> switch (f->type) {
> @@ -1354,8 +1353,7 @@ int audit_filter(int msgtype, unsigned int listtype)
> case AUDIT_SUBJ_SEN:
> case AUDIT_SUBJ_CLR:
> if (f->lsm_rule) {
> - security_task_getsecid(current, &sid);
> - lsmblob_init(&blob, sid);
> + security_task_getsecid(current, &blob);
> result = security_audit_rule_match(
> &blob, f->type,
> f->op, f->lsm_rule);
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 148733ec3c72..7112fe31684d 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -444,7 +444,6 @@ 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;
>
> @@ -628,10 +627,9 @@ static int audit_filter_rules(struct task_struct *tsk,
> logged upon error */
> if (f->lsm_rule) {
> if (need_sid) {
> - security_task_getsecid(tsk, &sid);
> + security_task_getsecid(tsk, &blob);
> need_sid = 0;
> }
> - lsmblob_init(&blob, sid);
> result = security_audit_rule_match(&blob,
> f->type,
> f->op,
> @@ -2365,12 +2363,15 @@ 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(t, &context->target_sid);
> + security_task_getsecid(t, &blob);
> + /* scaffolding - until target_sid is converted */
> + context->target_sid = blob.secid[0];
> memcpy(context->target_comm, t->comm, TASK_COMM_LEN);
> }
>
> @@ -2387,6 +2388,7 @@ int audit_signal_info(int sig, struct task_struct *t)
> struct audit_aux_data_pids *axp;
> struct audit_context *ctx = audit_context();
> kuid_t uid = current_uid(), auid, t_uid = task_uid(t);
> + struct lsmblob blob;
>
> if (auditd_test_task(t) &&
> (sig == SIGTERM || sig == SIGHUP ||
> @@ -2397,7 +2399,9 @@ int audit_signal_info(int sig, struct task_struct *t)
> audit_sig_uid = auid;
> else
> audit_sig_uid = uid;
> - security_task_getsecid(current, &audit_sig_sid);
> + security_task_getsecid(current, &blob);
> + /* scaffolding until audit_sig_sid is converted */
> + audit_sig_sid = blob.secid[0];
> }
>
> if (!audit_signals || audit_dummy_context())
> @@ -2410,7 +2414,9 @@ int audit_signal_info(int sig, 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(t, &ctx->target_sid);
> + security_task_getsecid(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;
> }
> @@ -2431,7 +2437,9 @@ int audit_signal_info(int sig, 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(t, &axp->target_sid[axp->pid_count]);
> + security_task_getsecid(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 2d8dd5b84457..2294aa9471e6 100644
> --- a/net/netlabel/netlabel_unlabeled.c
> +++ b/net/netlabel/netlabel_unlabeled.c
> @@ -1552,11 +1552,14 @@ 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_task_getsecid(current, &audit_info.secid);
> + security_task_getsecid(current, &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 4a397cde1a48..ab88baaaa50d 100644
> --- a/net/netlabel/netlabel_user.h
> +++ b/net/netlabel/netlabel_user.h
> @@ -48,7 +48,11 @@
> static inline void netlbl_netlink_auditinfo(struct sk_buff *skb,
> struct netlbl_audit *audit_info)
> {
> - security_task_getsecid(current, &audit_info->secid);
> + struct lsmblob blob;
> +
> + security_task_getsecid(current, &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 5fb7127bbe68..85c7692fc4a3 100644
> --- a/security/integrity/ima/ima_appraise.c
> +++ b/security/integrity/ima/ima_appraise.c
> @@ -51,11 +51,13 @@ bool is_ima_appraise_enabled(void)
> int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func)
> {
> u32 secid;
> + struct lsmblob blob;
>
> if (!ima_appraise)
> return 0;
>
> - security_task_getsecid(current, &secid);
> + security_task_getsecid(current, &blob);
> + lsmblob_secid(&blob, &secid);
> return ima_match_policy(inode, current_cred(), secid, func, mask,
> IMA_APPRAISE | IMA_HASH, NULL);
> }
> diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
> index 357edd140c09..fefa848cf0c7 100644
> --- a/security/integrity/ima/ima_main.c
> +++ b/security/integrity/ima/ima_main.c
> @@ -335,12 +335,13 @@ 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_task_getsecid(current, &secid);
> - return process_measurement(file, current_cred(), secid, NULL,
> - 0, MAY_EXEC, MMAP_CHECK);
> + security_task_getsecid(current, &blob);
> + /* scaffolding - until process_measurement changes */
> + return process_measurement(file, current_cred(), blob.secid[0],
> + NULL, 0, MAY_EXEC, MMAP_CHECK);
> }
>
> return 0;
> @@ -363,10 +364,12 @@ int ima_bprm_check(struct linux_binprm *bprm)
> {
> int ret;
> u32 secid;
> + struct lsmblob blob;
>
> - security_task_getsecid(current, &secid);
> - ret = process_measurement(bprm->file, current_cred(), secid, NULL, 0,
> - MAY_EXEC, BPRM_CHECK);
> + security_task_getsecid(current, &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;
>
> @@ -387,10 +390,11 @@ int ima_bprm_check(struct linux_binprm *bprm)
> */
> int ima_file_check(struct file *file, int mask)
> {
> - u32 secid;
> + struct lsmblob blob;
>
> - security_task_getsecid(current, &secid);
> - return process_measurement(file, current_cred(), secid, NULL, 0,
> + security_task_getsecid(current, &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);
> }
> @@ -499,7 +503,7 @@ 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;
>
> if (!file && read_id == READING_FIRMWARE) {
> if ((ima_appraise & IMA_APPRAISE_FIRMWARE) &&
> @@ -521,9 +525,10 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
> }
>
> func = read_idmap[read_id] ?: FILE_CHECK;
> - security_task_getsecid(current, &secid);
> - return process_measurement(file, current_cred(), secid, buf, size,
> - MAY_READ, func);
> + security_task_getsecid(current, &blob);
> + /* scaffolding until process_measurement changes */
> + return process_measurement(file, current_cred(), blob.secid[0], buf,
> + size, MAY_READ, func);
> }
>
> /**
> diff --git a/security/security.c b/security/security.c
> index 5245d4d1e799..2f123003b0b3 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -1712,10 +1712,16 @@ int security_task_getsid(struct task_struct *p)
> return call_int_hook(task_getsid, 0, p);
> }
>
> -void security_task_getsecid(struct task_struct *p, u32 *secid)
> +void security_task_getsecid(struct task_struct *p, struct lsmblob *blob)
> {
> - *secid = 0;
> - call_void_hook(task_getsecid, p, secid);
> + struct security_hook_list *hp;
> +
> + lsmblob_init(blob, 0);
> + hlist_for_each_entry(hp, &security_hook_heads.task_getsecid, list) {
> + if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
> + continue;
> + hp->hook.task_getsecid(p, &blob->secid[hp->lsmid->slot]);
> + }
> }
> EXPORT_SYMBOL(security_task_getsecid);
>
> --
> 2.20.1
>
--
Kees Cook
More information about the Linux-security-module-archive
mailing list