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: john.johansen@canonical.com, linux-kernel@vger.kernel.org,
linux-audit@redhat.com, sds@tycho.nsa.gov
Subject: [PATCH v30 20/28] binder: Pass LSM identifier for confirmation
Date: Tue, 23 Nov 2021 17:43:24 -0800 [thread overview]
Message-ID: <20211124014332.36128-21-casey@schaufler-ca.com> (raw)
In-Reply-To: <20211124014332.36128-1-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 caaee7f95514..7172d864579d 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -2762,6 +2762,7 @@ 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,
@@ -4132,6 +4133,26 @@ 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 d6b6b8cb7346..e3a0718ce17c 100644
--- a/drivers/android/binder_internal.h
+++ b/drivers/android/binder_internal.h
@@ -545,6 +545,7 @@ 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
--
2.31.1
--
Linux-audit mailing list
Linux-audit@redhat.com
https://listman.redhat.com/mailman/listinfo/linux-audit
next prev parent reply other threads:[~2021-11-24 2:05 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20211124014332.36128-1-casey.ref@schaufler-ca.com>
2021-11-24 1:43 ` [PATCH v30 00/28] LSM: Module stacking for AppArmor Casey Schaufler
2021-11-24 1:43 ` [PATCH v30 01/28] integrity: disassociate ima_filter_rule from security_audit_rule Casey Schaufler
2021-12-06 2:43 ` Paul Moore
2021-11-24 1:43 ` [PATCH v30 02/28] LSM: Infrastructure management of the sock security Casey Schaufler
2021-11-24 1:43 ` [PATCH v30 03/28] LSM: Add the lsmblob data structure Casey Schaufler
2021-12-06 2:44 ` Paul Moore
2021-11-24 1:43 ` [PATCH v30 04/28] LSM: provide lsm name and id slot mappings Casey Schaufler
2021-11-24 1:43 ` [PATCH v30 05/28] IMA: avoid label collisions with stacked LSMs Casey Schaufler
2021-11-24 1:43 ` [PATCH v30 06/28] LSM: Use lsmblob in security_audit_rule_match Casey Schaufler
2021-11-24 13:19 ` kernel test robot
2021-12-06 2:44 ` Paul Moore
2021-11-24 1:43 ` [PATCH v30 07/28] LSM: Use lsmblob in security_kernel_act_as Casey Schaufler
2021-11-24 1:43 ` [PATCH v30 08/28] LSM: Use lsmblob in security_secctx_to_secid Casey Schaufler
2021-11-24 1:43 ` [PATCH v30 09/28] LSM: Use lsmblob in security_secid_to_secctx Casey Schaufler
2021-11-24 1:43 ` [PATCH v30 10/28] LSM: Use lsmblob in security_ipc_getsecid Casey Schaufler
2021-11-24 1:43 ` [PATCH v30 11/28] LSM: Use lsmblob in security_task_getsecid Casey Schaufler
2021-11-24 1:43 ` [PATCH v30 12/28] LSM: Use lsmblob in security_inode_getsecid Casey Schaufler
2021-11-24 1:43 ` [PATCH v30 13/28] LSM: Use lsmblob in security_cred_getsecid Casey Schaufler
2021-11-24 1:43 ` [PATCH v30 14/28] LSM: Specify which LSM to display Casey Schaufler
2021-11-24 1:43 ` [PATCH v30 15/28] LSM: Ensure the correct LSM context releaser Casey Schaufler
2021-11-24 1:43 ` [PATCH v30 16/28] LSM: Use lsmcontext in security_secid_to_secctx Casey Schaufler
2021-11-24 1:43 ` [PATCH v30 17/28] LSM: Use lsmcontext in security_inode_getsecctx Casey Schaufler
2021-11-24 1:43 ` [PATCH v30 18/28] LSM: security_secid_to_secctx in netlink netfilter Casey Schaufler
2021-11-24 1:43 ` [PATCH v30 19/28] NET: Store LSM netlabel data in a lsmblob Casey Schaufler
2021-11-24 1:43 ` Casey Schaufler [this message]
2021-11-24 1:43 ` [PATCH v30 21/28] LSM: Extend security_secid_to_secctx to include module selection Casey Schaufler
2021-11-24 1:43 ` [PATCH v30 22/28] Audit: Keep multiple LSM data in audit_names Casey Schaufler
2021-12-06 2:44 ` Paul Moore
2021-11-24 1:43 ` [PATCH v30 23/28] Audit: Create audit_stamp structure Casey Schaufler
2021-12-06 2:44 ` Paul Moore
2021-11-24 1:43 ` [PATCH v30 24/28] Audit: Add framework for auxiliary records Casey Schaufler
2021-12-06 2:45 ` Paul Moore
2021-11-24 1:43 ` [PATCH v30 25/28] Audit: Add record for multiple task security contexts Casey Schaufler
2021-12-06 2:45 ` Paul Moore
2021-11-24 1:43 ` [PATCH v30 26/28] Audit: Add record for multiple object " Casey Schaufler
2021-11-24 7:41 ` kernel test robot
2021-11-24 13:40 ` kernel test robot
2021-12-06 2:45 ` Paul Moore
2021-11-24 1:43 ` [PATCH v30 27/28] LSM: Add /proc attr entry for full LSM context Casey Schaufler
2021-11-24 1:43 ` [PATCH v30 28/28] AppArmor: Remove the exclusive flag Casey Schaufler
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20211124014332.36128-21-casey@schaufler-ca.com \
--to=casey@schaufler-ca.com \
--cc=casey.schaufler@intel.com \
--cc=jmorris@namei.org \
--cc=john.johansen@canonical.com \
--cc=linux-audit@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=sds@tycho.nsa.gov \
--cc=selinux@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox