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
Subject: [PATCH 14/27] ACPI: Limit access to custom_method when the kernel is locked down
Date: Thu, 28 Feb 2019 15:11:50 -0800
Message-ID: <20190228231203.212359-14-matthewgarrett@google.com> (raw)
In-Reply-To: <20190228231203.212359-1-matthewgarrett@google.com>
From: Matthew Garrett <mjg59@srcf.ucam.org>
custom_method effectively allows arbitrary access to system memory, making
it possible for an attacker to circumvent restrictions on module loading.
Disable it if the kernel is locked down.
Signed-off-by: Matthew Garrett <mjg59@srcf.ucam.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: "Lee, Chun-Yi" <jlee@suse.com>
cc: linux-acpi@vger.kernel.org
---
drivers/acpi/custom_method.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/acpi/custom_method.c b/drivers/acpi/custom_method.c
index 4451877f83b6..ac8a90dc7096 100644
--- a/drivers/acpi/custom_method.c
+++ b/drivers/acpi/custom_method.c
@@ -29,6 +29,9 @@ static ssize_t cm_write(struct file *file, const char __user * user_buf,
struct acpi_table_header table;
acpi_status status;
+ if (kernel_is_locked_down("ACPI custom methods"))
+ return -EPERM;
+
if (!(*ppos)) {
/* parse the table header to get the table length */
if (count <= sizeof(struct acpi_table_header))
--
2.21.0.352.gf09ad66450-goog
next prev parent reply index
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-28 21:28 [PULL REQUEST] Lock down patches Matthew Garrett
2019-02-28 22:20 ` Mimi Zohar
2019-02-28 23:13 ` Matthew Garrett
2019-03-01 0:05 ` Mimi Zohar
2019-03-01 1:01 ` Matthew Garrett
2019-03-01 1:44 ` Mimi Zohar
2019-03-01 3:33 ` Matthew Garrett
2019-03-01 4:16 ` Mimi Zohar
2019-02-28 22:44 ` [PATCH 01/27] Add the ability to lock down access to the running kernel image Matthew Garrett
2019-02-28 22:44 ` [PATCH 02/27] Add a SysRq option to lift kernel lockdown Matthew Garrett
2019-02-28 23:10 ` [PATCH 01/27] Add the ability to lock down access to the running kernel image Matthew Garrett
2019-02-28 23:10 ` [PATCH 02/27] Add a SysRq option to lift kernel lockdown Matthew Garrett
2019-02-28 23:11 ` [PATCH 01/27] Add the ability to lock down access to the running kernel image Matthew Garrett
2019-02-28 23:11 ` [PATCH 02/27] Add a SysRq option to lift kernel lockdown Matthew Garrett
2019-02-28 23:11 ` [PATCH 01/27] Add the ability to lock down access to the running kernel image Matthew Garrett
2019-02-28 23:11 ` [PATCH 02/27] Add a SysRq option to lift kernel lockdown Matthew Garrett
2019-02-28 23:11 ` [PATCH 03/27] Enforce module signatures if the kernel is locked down Matthew Garrett
2019-02-28 23:11 ` [PATCH 04/27] Restrict /dev/{mem,kmem,port} when " Matthew Garrett
2019-02-28 23:11 ` [PATCH 05/27] kexec_load: Disable at runtime if " Matthew Garrett
2019-02-28 23:11 ` [PATCH 06/27] Copy secure_boot flag in boot params across kexec reboot Matthew Garrett
2019-02-28 23:11 ` [PATCH 07/27] kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE Matthew Garrett
2019-02-28 23:11 ` [PATCH 08/27] kexec_file: Restrict at runtime if the kernel is locked down Matthew Garrett
2019-03-01 2:05 ` Mimi Zohar
2019-02-28 23:11 ` [PATCH 09/27] hibernate: Disable when " Matthew Garrett
2019-03-19 22:15 ` Pavel Machek
2019-02-28 23:11 ` [PATCH 10/27] uswsusp: " Matthew Garrett
2019-02-28 23:11 ` [PATCH 11/27] PCI: Lock down BAR access " Matthew Garrett
2019-02-28 23:11 ` [PATCH 12/27] x86: Lock down IO port " Matthew Garrett
2019-02-28 23:11 ` [PATCH 13/27] x86/msr: Restrict MSR " Matthew Garrett
2019-02-28 23:11 ` Matthew Garrett [this message]
2019-02-28 23:11 ` [PATCH 15/27] acpi: Ignore acpi_rsdp kernel param when the kernel has been " Matthew Garrett
2019-02-28 23:11 ` [PATCH 16/27] acpi: Disable ACPI table override if the kernel is " Matthew Garrett
2019-02-28 23:11 ` [PATCH 17/27] acpi: Disable APEI error injection " Matthew Garrett
2019-02-28 23:11 ` [PATCH 18/27] Prohibit PCMCIA CIS storage when " Matthew Garrett
2019-02-28 23:11 ` [PATCH 19/27] Lock down TIOCSSERIAL Matthew Garrett
2019-02-28 23:11 ` [PATCH 20/27] Lock down module params that specify hardware parameters (eg. ioport) Matthew Garrett
2019-02-28 23:11 ` [PATCH 21/27] x86/mmiotrace: Lock down the testmmiotrace module Matthew Garrett
2019-02-28 23:11 ` [PATCH 22/27] Lock down /proc/kcore Matthew Garrett
2019-02-28 23:11 ` [PATCH 23/27] Lock down kprobes Matthew Garrett
2019-02-28 23:12 ` [PATCH 24/27] bpf: Restrict kernel image access functions when the kernel is locked down Matthew Garrett
2019-02-28 23:12 ` [PATCH 25/27] Lock down perf Matthew Garrett
2019-02-28 23:12 ` [PATCH 26/27] debugfs: Restrict debugfs when the kernel is locked down Matthew Garrett
2019-02-28 23:12 ` [PATCH 27/27] lockdown: Print current->comm in restriction messages Matthew Garrett
2019-02-28 23:24 ` [PULL REQUEST] Lock down patches Randy Dunlap
2019-03-04 22:10 ` Matthew Garrett
-- strict thread matches above, loose matches on Subject: below --
2019-03-06 23:58 [PULL REQUEST] Kernel lockdown patches for 5.2 Matthew Garrett
2019-03-06 23:59 ` [PATCH 14/27] ACPI: Limit access to custom_method when the kernel is locked down Matthew Garrett
2017-10-19 14:50 [PATCH 00/27] security, efi: Add kernel lockdown David Howells
2017-10-19 14:52 ` [PATCH 14/27] ACPI: Limit access to custom_method when the kernel is locked down David Howells
2017-10-20 6:45 ` joeyli
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