[23/27] Lock down kprobes

Message ID	20190228231203.212359-23-matthewgarrett@google.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-security-module-owner@kernel.org> Date: Thu, 28 Feb 2019 15:11:59 -0800 In-Reply-To: <20190228231203.212359-1-matthewgarrett@google.com> Message-Id: <20190228231203.212359-23-matthewgarrett@google.com> Mime-Version: 1.0 References: <CACdnJuvW47m3JvEcuEX1bsr+L2Ht9LDn_iCuPbHLOoaohOFW4Q@mail.gmail.com> <20190228231203.212359-1-matthewgarrett@google.com> Subject: [PATCH 23/27] Lock down kprobes 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

20190228231203.212359-23-matthewgarrett@google.com (mailing list archive)

State

New, archived

Headers

Date: Thu, 28 Feb 2019 15:11:59 -0800
In-Reply-To: <20190228231203.212359-1-matthewgarrett@google.com>
Message-Id: <20190228231203.212359-23-matthewgarrett@google.com>
Mime-Version: 1.0
References: 
 <CACdnJuvW47m3JvEcuEX1bsr+L2Ht9LDn_iCuPbHLOoaohOFW4Q@mail.gmail.com>
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Subject: [PATCH 23/27] Lock down kprobes
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, 11:11 p.m. UTC

From: David Howells <dhowells@redhat.com>

Disallow the creation of kprobes when the kernel is locked down by
preventing their registration.  This prevents kprobes from being used to
access kernel memory, either to make modifications or to steal crypto data.

Reported-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
---
 kernel/kprobes.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index f4ddfdd2d07e..6f66cca8e2c6 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1552,6 +1552,9 @@  int register_kprobe(struct kprobe *p)
 	struct module *probed_mod;
 	kprobe_opcode_t *addr;
 
+	if (kernel_is_locked_down("Use of kprobes"))
+		return -EPERM;
+
 	/* Adjust probe address from symbol */
 	addr = kprobe_addr(p);
 	if (IS_ERR(addr))

[23/27] Lock down kprobes

Commit Message

Patch