[24/27] Lock down perf

Message ID	20190325220954.29054-25-matthewgarrett@google.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-security-module-owner@kernel.org> Date: Mon, 25 Mar 2019 15:09:51 -0700 In-Reply-To: <20190325220954.29054-1-matthewgarrett@google.com> Message-Id: <20190325220954.29054-25-matthewgarrett@google.com> Mime-Version: 1.0 References: <20190325220954.29054-1-matthewgarrett@google.com> Subject: [PATCH 24/27] Lock down perf From: Matthew Garrett <matthewgarrett@google.com> To: jmorris@namei.org Cc: linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, dhowells@redhat.com, Matthew Garrett <matthewgarrett@google.com>, Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@redhat.com>, Arnaldo Carvalho de Melo <acme@kernel.org> Content-Type: text/plain; charset="UTF-8" Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk
Series	[PULL,REQUEST] Lockdown patches for 5.2 \| expand [PULL,REQUEST] Lockdown patches for 5.2 [02/27] Enforce module signatures if the kernel is locked down [03/27] Restrict /dev/{mem,kmem,port} when the kernel is locked down [04/27] kexec_load: Disable at runtime if the kernel is locked down [05/27] Copy secure_boot flag in boot params across kexec reboot [06/27] kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE [07/27] kexec_file: Restrict at runtime if the kernel is locked down [08/27] hibernate: Disable when the kernel is locked down [09/27] uswsusp: Disable when the kernel is locked down [10/27] PCI: Lock down BAR access when the kernel is locked down [11/27] x86: Lock down IO port access when the kernel is locked down [12/27] x86/msr: Restrict MSR access when the kernel is locked down [13/27] ACPI: Limit access to custom_method when the kernel is locked down [14/27] acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down [15/27] acpi: Disable ACPI table override if the kernel is locked down [16/27] acpi: Disable APEI error injection if the kernel is locked down [17/27] Prohibit PCMCIA CIS storage when the kernel is locked down [18/27] Lock down TIOCSSERIAL [19/27] Lock down module params that specify hardware parameters (eg. ioport) [20/27] x86/mmiotrace: Lock down the testmmiotrace module [21/27] Lock down /proc/kcore [22/27] Lock down kprobes [23/27] bpf: Restrict kernel image access functions when the kernel is locked down [24/27] Lock down perf [25/27] debugfs: Restrict debugfs when the kernel is locked down [26/27] lockdown: Print current->comm in restriction messages [27/27] kexec: Allow kexec_file() with appropriate IMA policy when locked down

Message ID

20190325220954.29054-25-matthewgarrett@google.com (mailing list archive)

State

New, archived

Headers

Date: Mon, 25 Mar 2019 15:09:51 -0700
In-Reply-To: <20190325220954.29054-1-matthewgarrett@google.com>
Message-Id: <20190325220954.29054-25-matthewgarrett@google.com>
Mime-Version: 1.0
References: <20190325220954.29054-1-matthewgarrett@google.com>
Subject: [PATCH 24/27] Lock down perf
From: Matthew Garrett <matthewgarrett@google.com>
To: jmorris@namei.org
Cc: linux-security-module@vger.kernel.org,
        linux-kernel@vger.kernel.org, dhowells@redhat.com,
        Matthew Garrett <matthewgarrett@google.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>
Content-Type: text/plain; charset="UTF-8"
Sender: owner-linux-security-module@vger.kernel.org
Precedence: bulk

Series

[PULL,REQUEST] Lockdown patches for 5.2 | expand

Commit Message

Matthew Garrett March 25, 2019, 10:09 p.m. UTC

From: David Howells <dhowells@redhat.com>

Disallow the use of certain perf facilities that might allow userspace to
access kernel data.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Matthew Garrett <matthewgarrett@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
---
 kernel/events/core.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 3cd13a30f732..7748c6f39992 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -10461,6 +10461,11 @@  SYSCALL_DEFINE5(perf_event_open,
 			return -EINVAL;
 	}
 
+	if ((attr.sample_type & PERF_SAMPLE_REGS_INTR) &&
+	    kernel_is_locked_down("PERF_SAMPLE_REGS_INTR"))
+		/* REGS_INTR can leak data, lockdown must prevent this */
+		return -EPERM;
+
 	/* Only privileged users can get physical addresses */
 	if ((attr.sample_type & PERF_SAMPLE_PHYS_ADDR) &&
 	    perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))

[24/27] Lock down perf

Commit Message

Patch