[25/27] Lock down perf

Message ID	20190228231203.212359-25-matthewgarrett@google.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-security-module-owner@kernel.org> Date: Thu, 28 Feb 2019 15:12:01 -0800 In-Reply-To: <20190228231203.212359-1-matthewgarrett@google.com> Message-Id: <20190228231203.212359-25-matthewgarrett@google.com> Mime-Version: 1.0 References: <CACdnJuvW47m3JvEcuEX1bsr+L2Ht9LDn_iCuPbHLOoaohOFW4Q@mail.gmail.com> <20190228231203.212359-1-matthewgarrett@google.com> Subject: [PATCH 25/27] 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 Content-Type: text/plain; charset="UTF-8" Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk
Series	[PULL,REQUEST] Lock down patches \| expand [PULL,REQUEST] Lock down patches [02/27] Add a SysRq option to lift kernel lockdown [03/27] Enforce module signatures if the kernel is locked down [04/27] Restrict /dev/{mem,kmem,port} when the kernel is locked down [05/27] kexec_load: Disable at runtime if the kernel is locked down [06/27] Copy secure_boot flag in boot params across kexec reboot [07/27] kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE [08/27] kexec_file: Restrict at runtime if the kernel is locked down [09/27] hibernate: Disable when the kernel is locked down [10/27] uswsusp: Disable when the kernel is locked down [11/27] PCI: Lock down BAR access when the kernel is locked down [12/27] x86: Lock down IO port access when the kernel is locked down [13/27] x86/msr: Restrict MSR access when the kernel is locked down [14/27] ACPI: Limit access to custom_method when the kernel is locked down [15/27] acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down [16/27] acpi: Disable ACPI table override if the kernel is locked down [17/27] acpi: Disable APEI error injection if the kernel is locked down [18/27] Prohibit PCMCIA CIS storage when the kernel is locked down [19/27] Lock down TIOCSSERIAL [20/27] Lock down module params that specify hardware parameters (eg. ioport) [21/27] x86/mmiotrace: Lock down the testmmiotrace module [22/27] Lock down /proc/kcore [23/27] Lock down kprobes [24/27] bpf: Restrict kernel image access functions when the kernel is locked down [25/27] Lock down perf [26/27] debugfs: Restrict debugfs when the kernel is locked down [27/27] lockdown: Print current->comm in restriction messages

Message ID

20190228231203.212359-25-matthewgarrett@google.com (mailing list archive)

State

New, archived

Headers

Date: Thu, 28 Feb 2019 15:12:01 -0800
In-Reply-To: <20190228231203.212359-1-matthewgarrett@google.com>
Message-Id: <20190228231203.212359-25-matthewgarrett@google.com>
Mime-Version: 1.0
References: 
 <CACdnJuvW47m3JvEcuEX1bsr+L2Ht9LDn_iCuPbHLOoaohOFW4Q@mail.gmail.com>
 <20190228231203.212359-1-matthewgarrett@google.com>
Subject: [PATCH 25/27] 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
Content-Type: text/plain; charset="UTF-8"
Sender: owner-linux-security-module@vger.kernel.org
Precedence: bulk

Series

[PULL,REQUEST] Lock down patches | expand

Commit Message

Matthew Garrett Feb. 28, 2019, 11:12 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>
---
 kernel/events/core.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 26d6edab051a..4265ce43bca4 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -10477,6 +10477,11 @@  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))

[25/27] Lock down perf

Commit Message

Patch