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 Subject: [PATCH v21 18/23] LSM: Verify LSM display sanity in binder Date: Mon, 12 Oct 2020 13:19:19 -0700 [thread overview] Message-ID: <20201012201924.71463-19-casey@schaufler-ca.com> (raw) In-Reply-To: <20201012201924.71463-1-casey@schaufler-ca.com> Verify that the tasks on the ends of a binder transaction use the same "display" 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 <sds@tycho.nsa.gov> 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 022af5ae8525..d8a813ba076c 100644 --- a/security/security.c +++ b/security/security.c @@ -790,9 +790,38 @@ 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_display = lsm_task_display(from); + int to_display = lsm_task_display(to); + + /* + * If the display 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_display == LSMBLOB_INVALID) + from_display = 0; + if (to_display == LSMBLOB_INVALID) + to_display = 0; + if (from_display != to_display) + return -EINVAL; + return call_int_hook(binder_transaction, 0, from, to); } -- 2.24.1
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-audit@redhat.com, sds@tycho.nsa.gov Subject: [PATCH v21 18/23] LSM: Verify LSM display sanity in binder Date: Mon, 12 Oct 2020 13:19:19 -0700 [thread overview] Message-ID: <20201012201924.71463-19-casey@schaufler-ca.com> (raw) In-Reply-To: <20201012201924.71463-1-casey@schaufler-ca.com> Verify that the tasks on the ends of a binder transaction use the same "display" 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 <sds@tycho.nsa.gov> 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 022af5ae8525..d8a813ba076c 100644 --- a/security/security.c +++ b/security/security.c @@ -790,9 +790,38 @@ 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_display = lsm_task_display(from); + int to_display = lsm_task_display(to); + + /* + * If the display 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_display == LSMBLOB_INVALID) + from_display = 0; + if (to_display == LSMBLOB_INVALID) + to_display = 0; + if (from_display != to_display) + return -EINVAL; + return call_int_hook(binder_transaction, 0, from, to); } -- 2.24.1 -- Linux-audit mailing list Linux-audit@redhat.com https://www.redhat.com/mailman/listinfo/linux-audit
next prev parent reply other threads:[~2020-10-12 20:39 UTC|newest] Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top [not found] <20201012201924.71463-1-casey.ref@schaufler-ca.com> 2020-10-12 20:19 ` [PATCH v21 00/23] LSM: Module stacking for AppArmor Casey Schaufler 2020-10-12 20:19 ` Casey Schaufler 2020-10-12 20:19 ` [PATCH v21 01/23] LSM: Infrastructure management of the sock security Casey Schaufler 2020-10-12 20:19 ` Casey Schaufler 2020-10-12 20:19 ` [PATCH v21 02/23] LSM: Create and manage the lsmblob data structure Casey Schaufler 2020-10-12 20:19 ` Casey Schaufler 2020-10-12 20:19 ` [PATCH v21 03/23] LSM: Use lsmblob in security_audit_rule_match Casey Schaufler 2020-10-12 20:19 ` Casey Schaufler 2020-10-12 20:19 ` [PATCH v21 04/23] LSM: Use lsmblob in security_kernel_act_as Casey Schaufler 2020-10-12 20:19 ` Casey Schaufler 2020-10-12 20:19 ` [PATCH v21 05/23] LSM: Use lsmblob in security_secctx_to_secid Casey Schaufler 2020-10-12 20:19 ` Casey Schaufler 2020-10-12 20:19 ` [PATCH v21 06/23] LSM: Use lsmblob in security_secid_to_secctx Casey Schaufler 2020-10-12 20:19 ` Casey Schaufler 2020-10-12 20:19 ` [PATCH v21 07/23] LSM: Use lsmblob in security_ipc_getsecid Casey Schaufler 2020-10-12 20:19 ` Casey Schaufler 2020-10-12 20:19 ` [PATCH v21 08/23] LSM: Use lsmblob in security_task_getsecid Casey Schaufler 2020-10-12 20:19 ` Casey Schaufler 2020-10-12 20:19 ` [PATCH v21 09/23] LSM: Use lsmblob in security_inode_getsecid Casey Schaufler 2020-10-12 20:19 ` Casey Schaufler 2020-10-12 20:19 ` [PATCH v21 10/23] LSM: Use lsmblob in security_cred_getsecid Casey Schaufler 2020-10-12 20:19 ` Casey Schaufler 2020-10-12 20:19 ` [PATCH v21 11/23] IMA: Change internal interfaces to use lsmblobs Casey Schaufler 2020-10-12 20:19 ` Casey Schaufler 2020-10-12 20:19 ` [PATCH v21 12/23] LSM: Specify which LSM to display Casey Schaufler 2020-10-12 20:19 ` Casey Schaufler 2020-10-12 20:19 ` [PATCH v21 13/23] LSM: Ensure the correct LSM context releaser Casey Schaufler 2020-10-12 20:19 ` Casey Schaufler 2020-10-12 20:19 ` [PATCH v21 14/23] LSM: Use lsmcontext in security_secid_to_secctx Casey Schaufler 2020-10-12 20:19 ` Casey Schaufler 2020-10-12 20:19 ` [PATCH v21 15/23] LSM: Use lsmcontext in security_inode_getsecctx Casey Schaufler 2020-10-12 20:19 ` Casey Schaufler 2020-10-12 20:19 ` [PATCH v21 16/23] LSM: security_secid_to_secctx in netlink netfilter Casey Schaufler 2020-10-12 20:19 ` Casey Schaufler 2020-10-12 20:19 ` [PATCH v21 17/23] NET: Store LSM netlabel data in a lsmblob Casey Schaufler 2020-10-12 20:19 ` Casey Schaufler 2020-10-12 20:19 ` Casey Schaufler [this message] 2020-10-12 20:19 ` [PATCH v21 18/23] LSM: Verify LSM display sanity in binder Casey Schaufler 2020-10-12 20:19 ` [PATCH v21 19/23] audit: add support for non-syscall auxiliary records Casey Schaufler 2020-10-12 20:19 ` Casey Schaufler 2020-10-12 20:19 ` [PATCH v21 20/23] Audit: Add new record for multiple process LSM attributes Casey Schaufler 2020-10-12 20:19 ` Casey Schaufler 2020-10-12 20:19 ` [PATCH v21 21/23] Audit: Add a new record for multiple object " Casey Schaufler 2020-10-12 20:19 ` Casey Schaufler 2020-10-12 20:19 ` [PATCH v21 22/23] LSM: Add /proc attr entry for full LSM context Casey Schaufler 2020-10-12 20:19 ` Casey Schaufler 2020-10-12 20:19 ` [PATCH v21 23/23] AppArmor: Remove the exclusive flag Casey Schaufler 2020-10-12 20:19 ` Casey Schaufler 2020-10-29 11:26 ` [PATCH v21 00/23] LSM: Module stacking for AppArmor John Johansen 2020-10-29 11:26 ` John Johansen
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