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, sds@tycho.nsa.gov, linux-kernel@vger.kernel.org, Stephen Smalley <stephen.smalley.work@gmail.com> Subject: [PATCH v29 20/28] LSM: Verify LSM display sanity in binder Date: Fri, 24 Sep 2021 10:54:33 -0700 [thread overview] Message-ID: <20210924175441.7943-21-casey@schaufler-ca.com> (raw) In-Reply-To: <20210924175441.7943-1-casey@schaufler-ca.com> Verify that the tasks on the ends of a binder transaction use the same "interface_lsm" security module. This prevents confusion of security "contexts". Reviewed-by: Kees Cook <keescook@chromium.org> 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> --- security/security.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/security/security.c b/security/security.c index a61477c6b0f6..155da0e9b778 100644 --- a/security/security.c +++ b/security/security.c @@ -860,9 +860,38 @@ int security_binder_set_context_mgr(struct task_struct *mgr) return call_int_hook(binder_set_context_mgr, 0, mgr); } +/** + * security_binder_transaction - Binder driver transaction check + * @from: source of the transaction + * @to: destination of the transaction + * + * Verify that the tasks have the same LSM "display", then + * call the security module hooks. + * + * Returns -EINVAL if the displays don't match, or the + * result of the security module checks. + */ int security_binder_transaction(struct task_struct *from, struct task_struct *to) { + int from_ilsm = lsm_task_ilsm(from); + int to_ilsm = lsm_task_ilsm(to); + + /* + * If the ilsm is LSMBLOB_INVALID the first module that has + * an entry is used. This will be in the 0 slot. + * + * This is currently only required if the server has requested + * peer contexts, but it would be unwieldly to have too much of + * the binder driver detail here. + */ + if (from_ilsm == LSMBLOB_INVALID) + from_ilsm = 0; + if (to_ilsm == LSMBLOB_INVALID) + to_ilsm = 0; + if (from_ilsm != to_ilsm) + return -EINVAL; + return call_int_hook(binder_transaction, 0, from, to); } -- 2.31.1
WARNING: multiple messages have this Message-ID (diff)
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 v29 20/28] LSM: Verify LSM display sanity in binder Date: Fri, 24 Sep 2021 10:54:33 -0700 [thread overview] Message-ID: <20210924175441.7943-21-casey@schaufler-ca.com> (raw) In-Reply-To: <20210924175441.7943-1-casey@schaufler-ca.com> Verify that the tasks on the ends of a binder transaction use the same "interface_lsm" security module. This prevents confusion of security "contexts". Reviewed-by: Kees Cook <keescook@chromium.org> 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> --- security/security.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/security/security.c b/security/security.c index a61477c6b0f6..155da0e9b778 100644 --- a/security/security.c +++ b/security/security.c @@ -860,9 +860,38 @@ int security_binder_set_context_mgr(struct task_struct *mgr) return call_int_hook(binder_set_context_mgr, 0, mgr); } +/** + * security_binder_transaction - Binder driver transaction check + * @from: source of the transaction + * @to: destination of the transaction + * + * Verify that the tasks have the same LSM "display", then + * call the security module hooks. + * + * Returns -EINVAL if the displays don't match, or the + * result of the security module checks. + */ int security_binder_transaction(struct task_struct *from, struct task_struct *to) { + int from_ilsm = lsm_task_ilsm(from); + int to_ilsm = lsm_task_ilsm(to); + + /* + * If the ilsm is LSMBLOB_INVALID the first module that has + * an entry is used. This will be in the 0 slot. + * + * This is currently only required if the server has requested + * peer contexts, but it would be unwieldly to have too much of + * the binder driver detail here. + */ + if (from_ilsm == LSMBLOB_INVALID) + from_ilsm = 0; + if (to_ilsm == LSMBLOB_INVALID) + to_ilsm = 0; + if (from_ilsm != to_ilsm) + return -EINVAL; + return call_int_hook(binder_transaction, 0, from, to); } -- 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:[~2021-09-24 18:17 UTC|newest] Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top [not found] <20210924175441.7943-1-casey.ref@schaufler-ca.com> 2021-09-24 17:54 ` [PATCH v29 00/28] LSM: Module stacking for AppArmor Casey Schaufler 2021-09-24 17:54 ` Casey Schaufler 2021-09-24 17:54 ` [PATCH v29 01/28] LSM: Infrastructure management of the sock security Casey Schaufler 2021-09-24 17:54 ` Casey Schaufler 2021-09-24 17:54 ` [PATCH v29 02/28] LSM: Add the lsmblob data structure Casey Schaufler 2021-09-24 17:54 ` Casey Schaufler 2021-09-24 17:54 ` [PATCH v29 03/28] LSM: provide lsm name and id slot mappings Casey Schaufler 2021-09-24 17:54 ` Casey Schaufler 2021-09-24 17:54 ` [PATCH v29 04/28] IMA: avoid label collisions with stacked LSMs Casey Schaufler 2021-09-24 17:54 ` Casey Schaufler 2021-09-24 17:54 ` [PATCH v29 05/28] LSM: Use lsmblob in security_audit_rule_match Casey Schaufler 2021-09-24 17:54 ` Casey Schaufler 2021-09-24 17:54 ` [PATCH v29 06/28] LSM: Use lsmblob in security_kernel_act_as Casey Schaufler 2021-09-24 17:54 ` Casey Schaufler 2021-09-24 17:54 ` [PATCH v29 07/28] LSM: Use lsmblob in security_secctx_to_secid Casey Schaufler 2021-09-24 17:54 ` Casey Schaufler 2021-09-24 17:54 ` [PATCH v29 08/28] LSM: Use lsmblob in security_secid_to_secctx Casey Schaufler 2021-09-24 17:54 ` Casey Schaufler 2021-09-24 17:54 ` [PATCH v29 09/28] LSM: Use lsmblob in security_ipc_getsecid Casey Schaufler 2021-09-24 17:54 ` Casey Schaufler 2021-09-24 17:54 ` [PATCH v29 10/28] LSM: Use lsmblob in security_task_getsecid Casey Schaufler 2021-09-24 17:54 ` Casey Schaufler 2021-09-24 17:54 ` [PATCH v29 11/28] LSM: Use lsmblob in security_inode_getsecid Casey Schaufler 2021-09-24 17:54 ` Casey Schaufler 2021-09-24 17:54 ` [PATCH v29 12/28] LSM: Use lsmblob in security_cred_getsecid Casey Schaufler 2021-09-24 17:54 ` Casey Schaufler 2021-09-24 17:54 ` [PATCH v29 13/28] IMA: Change internal interfaces to use lsmblobs Casey Schaufler 2021-09-24 17:54 ` Casey Schaufler 2021-09-24 17:54 ` [PATCH v29 14/28] LSM: Specify which LSM to display Casey Schaufler 2021-09-24 17:54 ` Casey Schaufler 2021-09-24 17:54 ` [PATCH v29 15/28] LSM: Ensure the correct LSM context releaser Casey Schaufler 2021-09-24 17:54 ` Casey Schaufler 2021-09-24 17:54 ` [PATCH v29 16/28] LSM: Use lsmcontext in security_secid_to_secctx Casey Schaufler 2021-09-24 17:54 ` Casey Schaufler 2021-09-24 17:54 ` [PATCH v29 17/28] LSM: Use lsmcontext in security_inode_getsecctx Casey Schaufler 2021-09-24 17:54 ` Casey Schaufler 2021-09-24 17:54 ` [PATCH v29 18/28] LSM: security_secid_to_secctx in netlink netfilter Casey Schaufler 2021-09-24 17:54 ` Casey Schaufler 2021-09-24 17:54 ` [PATCH v29 19/28] NET: Store LSM netlabel data in a lsmblob Casey Schaufler 2021-09-24 17:54 ` Casey Schaufler 2021-09-24 17:54 ` Casey Schaufler [this message] 2021-09-24 17:54 ` [PATCH v29 20/28] LSM: Verify LSM display sanity in binder Casey Schaufler 2021-09-24 17:54 ` [PATCH v29 21/28] LSM: Extend security_secid_to_secctx to include module selection Casey Schaufler 2021-09-24 17:54 ` Casey Schaufler 2021-09-24 17:54 ` [PATCH v29 22/28] Audit: Keep multiple LSM data in audit_names Casey Schaufler 2021-09-24 17:54 ` Casey Schaufler 2021-09-24 17:54 ` [PATCH v29 23/28] Audit: Create audit_stamp structure Casey Schaufler 2021-09-24 17:54 ` Casey Schaufler 2021-09-24 17:54 ` [PATCH v29 24/28] Audit: Add framework for auxiliary records Casey Schaufler 2021-09-24 17:54 ` Casey Schaufler 2021-09-24 17:54 ` [PATCH v29 25/28] Audit: Add record for multiple task security contexts Casey Schaufler 2021-09-24 17:54 ` Casey Schaufler 2021-09-24 17:54 ` [PATCH v29 26/28] Audit: Add record for multiple object " Casey Schaufler 2021-09-24 17:54 ` Casey Schaufler 2021-09-24 17:54 ` [PATCH v29 27/28] LSM: Add /proc attr entry for full LSM context Casey Schaufler 2021-09-24 17:54 ` Casey Schaufler 2021-09-24 17:54 ` [PATCH v29 28/28] AppArmor: Remove the exclusive flag Casey Schaufler 2021-09-24 17:54 ` Casey Schaufler
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