From: Casey Schaufler <casey@schaufler-ca.com>
To: casey.schaufler@intel.com, jmorris@namei.org,
linux-security-module@vger.kernel.org, selinux@vger.kernel.org
Cc: casey@schaufler-ca.com, linux-audit@redhat.com,
keescook@chromium.org, john.johansen@canonical.com,
penguin-kernel@i-love.sakura.ne.jp, paul@paul-moore.com,
stephen.smalley.work@gmail.com, linux-kernel@vger.kernel.org
Subject: [PATCH v36 21/33] binder: Pass LSM identifier for confirmation
Date: Thu, 9 Jun 2022 16:01:34 -0700 [thread overview]
Message-ID: <20220609230146.319210-22-casey@schaufler-ca.com> (raw)
In-Reply-To: <20220609230146.319210-1-casey@schaufler-ca.com>
Send an identifier for the security module interface_lsm
along with the security context. This allows the receiver
to verify that the receiver and the sender agree on which
security module's context is being used. If they don't
agree the message is rejected.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
drivers/android/binder.c | 21 +++++++++++++++++++++
drivers/android/binder_internal.h | 1 +
2 files changed, 22 insertions(+)
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 8ae1a624cd37..f2a0faf6d9c6 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -3107,6 +3107,7 @@ static void binder_transaction(struct binder_proc *proc,
ALIGN(extra_buffers_size, sizeof(void *)) -
ALIGN(lsmctx.len, sizeof(u64));
+ t->security_interface = lsm_task_ilsm(current);
t->security_ctx = (uintptr_t)t->buffer->user_data + buf_offset;
err = binder_alloc_copy_to_buffer(&target_proc->alloc,
t->buffer, buf_offset,
@@ -4552,6 +4553,26 @@ static int binder_thread_read(struct binder_proc *proc,
tr.secctx = t->security_ctx;
if (t->security_ctx) {
+ int to_ilsm = lsm_task_ilsm(current);
+ int from_ilsm = t->security_interface;
+
+ if (to_ilsm == LSMBLOB_INVALID)
+ to_ilsm = 0;
+ if (from_ilsm == LSMBLOB_INVALID)
+ from_ilsm = 0;
+ /*
+ * The sender provided a security context from
+ * a different security module than the one this
+ * process wants to report if these don't match.
+ */
+ if (from_ilsm != to_ilsm) {
+ if (t_from)
+ binder_thread_dec_tmpref(t_from);
+
+ binder_cleanup_transaction(t, "security context mismatch",
+ BR_FAILED_REPLY);
+ return -EINVAL;
+ }
cmd = BR_TRANSACTION_SEC_CTX;
trsize = sizeof(tr);
}
diff --git a/drivers/android/binder_internal.h b/drivers/android/binder_internal.h
index 8dc0bccf8513..7233bfdb72db 100644
--- a/drivers/android/binder_internal.h
+++ b/drivers/android/binder_internal.h
@@ -550,6 +550,7 @@ struct binder_transaction {
long saved_priority;
kuid_t sender_euid;
struct list_head fd_fixups;
+ int security_interface;
binder_uintptr_t security_ctx;
/**
* @lock: protects @from, @to_proc, and @to_thread
--
2.35.1
next prev parent reply other threads:[~2022-06-09 23:14 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20220609230146.319210-1-casey.ref@schaufler-ca.com>
2022-06-09 23:01 ` [PATCH v36 00/33] LSM: Module stacking for AppArmor Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 01/33] integrity: disassociate ima_filter_rule from security_audit_rule Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 02/33] LSM: Infrastructure management of the sock security Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 03/33] LSM: Add the lsmblob data structure Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 04/33] LSM: provide lsm name and id slot mappings Casey Schaufler
2022-06-10 7:51 ` kernel test robot
2022-06-09 23:01 ` [PATCH v36 05/33] IMA: avoid label collisions with stacked LSMs Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 06/33] LSM: Use lsmblob in security_audit_rule_match Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 07/33] LSM: Use lsmblob in security_kernel_act_as Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 08/33] LSM: Use lsmblob in security_secctx_to_secid Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 09/33] LSM: Use lsmblob in security_secid_to_secctx Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 10/33] LSM: Use lsmblob in security_ipc_getsecid Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 11/33] LSM: Use lsmblob in security_current_getsecid Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 12/33] LSM: Use lsmblob in security_inode_getsecid Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 13/33] LSM: Use lsmblob in security_cred_getsecid Casey Schaufler
2022-06-12 19:35 ` kernel test robot
2022-06-09 23:01 ` [PATCH v36 14/33] LSM: Specify which LSM to display Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 15/33] LSM: Ensure the correct LSM context releaser Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 16/33] LSM: Use lsmcontext in security_secid_to_secctx Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 17/33] LSM: Use lsmcontext in security_inode_getsecctx Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 18/33] LSM: Use lsmcontext in security_dentry_init_security Casey Schaufler
2022-06-10 3:05 ` kernel test robot
2022-06-23 7:09 ` Dan Carpenter
2022-06-09 23:01 ` [PATCH v36 19/33] LSM: security_secid_to_secctx in netlink netfilter Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 20/33] NET: Store LSM netlabel data in a lsmblob Casey Schaufler
2022-06-09 23:01 ` Casey Schaufler [this message]
2022-06-09 23:01 ` [PATCH v36 22/33] LSM: Extend security_secid_to_secctx to include module selection Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 23/33] Audit: Keep multiple LSM data in audit_names Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 24/33] Audit: Create audit_stamp structure Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 25/33] LSM: Add a function to report multiple LSMs Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 26/33] Audit: Allow multiple records in an audit_buffer Casey Schaufler
2022-06-10 21:04 ` Paul Moore
2022-06-09 23:01 ` [PATCH v36 27/33] Audit: Add record for multiple task security contexts Casey Schaufler
2022-06-10 21:06 ` Paul Moore
2022-06-09 23:01 ` [PATCH v36 28/33] audit: multiple subject lsm values for netlabel Casey Schaufler
2022-06-10 21:10 ` Paul Moore
2022-06-09 23:01 ` [PATCH v36 29/33] Audit: Add record for multiple object contexts Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 30/33] netlabel: Use a struct lsmblob in audit data Casey Schaufler
2022-06-10 21:12 ` Paul Moore
2022-06-09 23:01 ` [PATCH v36 31/33] LSM: Removed scaffolding function lsmcontext_init Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 32/33] LSM: Add /proc attr entry for full LSM context Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 33/33] AppArmor: Remove the exclusive flag Casey Schaufler
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