From: Matthew Garrett <matthewgarrett@google.com>
To: jmorris@namei.org
Cc: linux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-api@vger.kernel.org,
David Howells <dhowells@redhat.com>,
Matthew Garrett <mjg59@google.com>,
Kees Cook <keescook@chromium.org>
Subject: [PATCH V35 21/29] Lock down /proc/kcore
Date: Mon, 15 Jul 2019 12:59:38 -0700 [thread overview]
Message-ID: <20190715195946.223443-22-matthewgarrett@google.com> (raw)
In-Reply-To: <20190715195946.223443-1-matthewgarrett@google.com>
From: David Howells <dhowells@redhat.com>
Disallow access to /proc/kcore when the kernel is locked down to prevent
access to cryptographic data. This is limited to lockdown
confidentiality mode and is still permitted in integrity mode.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Matthew Garrett <mjg59@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
---
fs/proc/kcore.c | 5 +++++
include/linux/security.h | 1 +
security/lockdown/lockdown.c | 1 +
3 files changed, 7 insertions(+)
diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c
index f5834488b67d..ee2c576cc94e 100644
--- a/fs/proc/kcore.c
+++ b/fs/proc/kcore.c
@@ -31,6 +31,7 @@
#include <linux/ioport.h>
#include <linux/memory.h>
#include <linux/sched/task.h>
+#include <linux/security.h>
#include <asm/sections.h>
#include "internal.h"
@@ -545,6 +546,10 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos)
static int open_kcore(struct inode *inode, struct file *filp)
{
+ int ret = security_locked_down(LOCKDOWN_KCORE);
+
+ if (ret)
+ return ret;
if (!capable(CAP_SYS_RAWIO))
return -EPERM;
diff --git a/include/linux/security.h b/include/linux/security.h
index 3f7b6a4cd65a..f0cffd0977d3 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -116,6 +116,7 @@ enum lockdown_reason {
LOCKDOWN_MODULE_PARAMETERS,
LOCKDOWN_MMIOTRACE,
LOCKDOWN_INTEGRITY_MAX,
+ LOCKDOWN_KCORE,
LOCKDOWN_CONFIDENTIALITY_MAX,
};
diff --git a/security/lockdown/lockdown.c b/security/lockdown/lockdown.c
index e725f63c29d2..9c097240a3a6 100644
--- a/security/lockdown/lockdown.c
+++ b/security/lockdown/lockdown.c
@@ -31,6 +31,7 @@ static char *lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1] = {
[LOCKDOWN_MODULE_PARAMETERS] = "unsafe module parameters",
[LOCKDOWN_MMIOTRACE] = "unsafe mmio",
[LOCKDOWN_INTEGRITY_MAX] = "integrity",
+ [LOCKDOWN_KCORE] = "/proc/kcore access",
[LOCKDOWN_CONFIDENTIALITY_MAX] = "confidentiality",
};
--
2.22.0.510.g264f2c817a-goog
next prev parent reply other threads:[~2019-07-15 20:01 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-15 19:59 [PATCH V35 00/29] Kernel lockdown functionality Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 01/29] security: Support early LSMs Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 02/29] security: Add a "locked down" LSM hook Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 03/29] security: Add a static lockdown policy LSM Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 04/29] Enforce module signatures if the kernel is locked down Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 05/29] Restrict /dev/{mem,kmem,port} when " Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 06/29] kexec_load: Disable at runtime if " Matthew Garrett
2019-07-15 19:59 ` Matthew Garrett
2019-07-15 19:59 ` Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 07/29] Copy secure_boot flag in boot params across kexec reboot Matthew Garrett
2019-07-15 19:59 ` Matthew Garrett
2019-07-15 19:59 ` Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 08/29] kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE Matthew Garrett
2019-07-15 19:59 ` Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 09/29] kexec_file: Restrict at runtime if the kernel is locked down Matthew Garrett
2019-07-15 19:59 ` Matthew Garrett
2019-07-15 19:59 ` Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 10/29] hibernate: Disable when " Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 11/29] PCI: Lock down BAR access " Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 12/29] x86: Lock down IO port " Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 13/29] x86/msr: Restrict MSR " Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 14/29] ACPI: Limit access to custom_method " Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 15/29] acpi: Ignore acpi_rsdp kernel param when the kernel has been " Matthew Garrett
2019-07-16 2:59 ` Dave Young
2019-07-16 20:34 ` Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 16/29] acpi: Disable ACPI table override if the kernel is " Matthew Garrett
2019-07-15 19:59 ` Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 17/29] Prohibit PCMCIA CIS storage when " Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 18/29] Lock down TIOCSSERIAL Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 19/29] Lock down module params that specify hardware parameters (eg. ioport) Matthew Garrett
2019-07-15 23:26 ` James Morris
2019-07-15 19:59 ` [PATCH V35 20/29] x86/mmiotrace: Lock down the testmmiotrace module Matthew Garrett
2019-07-15 19:59 ` Matthew Garrett [this message]
2019-07-15 19:59 ` [PATCH V35 22/29] Lock down tracing and perf kprobes when in confidentiality mode Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 23/29] bpf: Restrict bpf when kernel lockdown is " Matthew Garrett
2019-07-15 22:54 ` Daniel Borkmann
2019-07-16 20:32 ` Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 24/29] Lock down perf when " Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 25/29] kexec: Allow kexec_file() with appropriate IMA policy when locked down Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 26/29] debugfs: Restrict debugfs when the kernel is " Matthew Garrett
2019-07-15 23:17 ` James Morris
2019-07-15 19:59 ` [PATCH V35 27/29] tracefs: Restrict tracefs " Matthew Garrett
2019-07-16 23:14 ` Steven Rostedt
2019-07-16 23:22 ` Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 28/29] efi: Restrict efivar_ssdt_load " Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 29/29] lockdown: Print current->comm in restriction messages Matthew Garrett
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